From some of the comments, I believe you're wanting to discount / ignore the difference in velocity of the Earth's rotation. Beyond that, yes, you still have much to worry about.
It's not the slide that gets you. It's the sudden stop at the end.
Deceleration for Mr. Teleporter from a jet airplane traveling at about 570 mph (917 kmh) to 0 at home, assuming it takes 3 inches for the body to fully decelerate, would be over 43444 G of force. That's... way beyond merely fatal. Your traveler hits the wall hard enough to go through the wall and possibly the next wall. Though he won't know, since he cannot possibly even begin survive that at all. In fact, he'll be a rather disgusting smear mixed into the debris from the wall(s). I suspect there won't be enough solid mass (bones) left over to recognize he was even human. Picture a water balloon exploding against a brick wall.
Similarly, if he's at home and suddenly wakes up, realizes he missed his flight and somehow can mentally picture the right plane (given they all look alike, that's unlikely in the extreme), he's going to suddenly appear sitting calmly in a seat that's going 570 or so mph, but he's at complete rest. I suspect the forces involved are more than sufficient to rip an entire line of seats out of their moorings to the plane's floor and even rip them out the back of the plane. Either way, your teleporter (and probably many other people) just died horrifically. But, at least its over quickly. Again, his body will be converted into a gooey mess in the initial impact between his back and the chair.
That 570 mph sudden stop translates to about 29 823 142 Newtons or 6 704 511 pounds of force on impact. That's about 7 kg of TNT in equivalent energy you've just introduced into either Mr. Teleporter's home and/or airplane.
Maybe a less extreme example won't be so... messy?
Mr. Teleporter is in his car and realizes he forgot to grab his mug of coffee off the kitchen counter. Oops. Well, no problem. He's a commuter, but this week he's a passenger, not the drive. No one will mind if he pops back to the house, grabs his coffee, and then pops back into the car, right?
If their commute manages to get up to 70 mph on the highway (about 113 kph), he's going to appear in the kitchen going 70 mph and have a sudden and dramatically bad (but short) day. He will slide into the kitchen counter with roughly 655 Gs of force, give or take. If he has a kitchen counter that's well made at waist height, is upper body will be torn from the lower body, to impact somewhere else downrange with much less force. So the body will be recognizable and possibly even identifiable. But the bottom half just destroyed the kitchen counter, converting it all to a messy, gooey, pulp of debris.
He strikes the kitchen with almost 450 000 Newtons of force (101 115 lb. or about 450 kJ... that's about 0.11 kg of TNT). As far as I can find via Google, it takes about 1500 lb of force to break a typical 2x4 wall stud. So at 70 mph, he's going way more than fast enough to go through a wall. But then everything gets way too messy to determine whether he retains sufficient mass or velocity to continue going through wall(s) after that.
We can slow him down further, of course. My morning commute, on interstates, often drags along at about 25 mph (40 kph). That same bounce-to-kitchen event results in about 83.4 G when going from 25 to 0 mph. That's still well into potentially fatal territory, but maybe his now-widowed wife won't have to completely rebuild the kitchen out of his life insurance policy funds. Maybe.
As a point of reference, the highest Gs ever survived, according to Google, is 92 G during an Indy Car crash. This describes how his car hit at 214g, but his ear sensors measured 92g, resulting in multiple broken bones (femur, sternum, vertebra, and ankles). And that's with a great deal of safety equipment specifically designed to protect the driver from just this sort of thing. Your teleporter, wearing their best business-casual work clothing and without any sort of helmet, etc., isn't going to be so lucky (if you could even call an 18-month recovery from so many broken bones "lucky.") Note too that surviving high Gs requires physical training, so your typical office commuter won't make it out alive from that sudden 46 G event.
From this speed, he's going to strike with a force of about 57 370 Newtons (12 897 lb., 57 kJ, or about 14 g of TNT).
At 15 mph (24 kph), the impact Gs from suddenly sliding into a wall or other obstacle drop to a potentially survivable 30 G. But that's going to depend on what they hit (a wall spreads the force out more evenly, while striking a counter is probably completely fatal) and how tough they are. Regardless, they're going to suffer major, life-threatening injuries even at that relatively low speed.
Here, we've brought the impact force down to about a mere 20 653 Newtons (4 643 lb., 21 kJ or about 5 g of TNT).
At 10 mph (16 kph), we're down to about 13 G. That's painful but survivable, with about 9179 Newtons of impact force (2064 lb. or 2.2 g of TNT). But I wouldn't want to be going anywhere above that when I teleported.
Note, too, that if he's dumb enough to jump into the kitchen and misjudges his position, then there's now a mass from the kitchen that's sitting at rest in the car and about to strike the seat back he just left or the windshield with those same Gs, which will be destructive to the car and will likely pose a serious distraction to the driver.
If this power is held by a significant percentage of the population, there would be laws and public service announcements and stuff to prevent idiots from doing this sort of thing...
Teleporting with momentum is a bad idea.
Friends don't let friends teleport from moving vehicles.
A few commenters talk about surviving car crashes at higher speeds than above. I just want to mention that in a modern car, the vehicle is specifically designed with crumple zones, air bags, safety restraints, and numerous other safety features. All of this means that, in the split-second timing of the crash, the driver experiences far fewer Gs of force than the total potential Gs of two vehicles colliding. Unless your teleporter has the forethought to wrap themselves in bubble wrap (do NOT try this at home), they won't get the benefit of deceleration until their front half collides with the wall or counter. They instead get to let their internal organs and skeletal system absorb all of that energy all at once.
git rebase --teleport? $\endgroup$