I know nothing, wild speculation follows.

I'm pretty sure it's "easy" to tell an entrance from an exit, especially with a hollow point bullet (basically like an explosion out of the exit). Even without the explosion thing, I'd be shocked to learn that there are not tell-tale signs because an object pushing inward at a high speed will leave the tissue at certain angles, like maybe the soft tissue caved a little inward around the entrance, the bones broken in the direction the bullet was traveling, that sort of thing.

But all those thing depend on the object being ballistic, like a fast moving object flying through the body. With a "laser beam" sort of wound, I'm not sure any of that would apply.

I assume that looking at a wound caused by a laser would be pretty baffling -- a roughly cylindrical, cauterized void with no apparent directionality. Even if the cause wasn't clear, I think it would look weird enough for a professional to say "Wait, something is super weird here."