Yes, easily.
If I would need to fist-fight Bruce Lee while I'm a psionic and he isn't, all I can probably do is see my demise in slow motion. Seeing and reacting gives great advantages, but without the training giving me the speed, strength and skill to back it up, I'll probably be beat down. The same is true for swords.
Swords give more considerations. Seeing it slow can make you over or underestimate the power behind a blow. You can more easily injure yourself with overextending, a parry of a too hard blowespecially as only their strenght is improved. Their durability isn't, making it dangerous to use full strength and possibly breaking your own bones or ripping off the likeligaments. Being able to dodge is nice, but you might duck or something similar that accidentally put you out of balance, or a counterstrike with too little power.
With a trained opponent the psionic will have a good chance thanks to bullet time and their incredible strength, but as the psionic isn't trained there are a high amount of pitfals. The trained opponent doesn't need to be trained in fighting psionic persons, but just be very good at swords with an agressive style to win. If the psionic can go first, it looks a lot more dire, but as said before the raw strength can be a detriment, so a good block against a bad swing of the psionic might injure the psionic immensely. All that being said, being a psionic still gives massive advantages that make him/her an impressive match against skilled opponents.
Incidentally, other weapons that make use of the pitfalls of (untrained) psionics might pop up. Have a thought if a sword would be most logical.