QUOTE
It's completely impossible for Trevor's power to be cutting-heads open. It's ridiculous to say anything like this. How could Sylar have used Trevor's power to steal Trevor's power? It's beyond stupid!!
Your reasoning is infallible. I concede to your point.
But really..
QUOTE (HeroesWiki)
Trevor is able to shatter items from at least a few meters away (Villains). The exact mechanism behind the shattering is unknown. He has only been seen to shatter glass items; what effect this power would have on less fragile materials is unknown, although he did seem to think it would make an effective weapon when threatened by Sylar. It's unknown whether it can affect non-solid objects.
His ability is not known completely. I believe that, with a bit of control, the force of Trevor's ability could be less destructive than what was used on the glasses, and we know that Sylar knows "how things work", so...
QUOTE (HeroesWiki)
To use his ability, Trevor aims at his target with his index finger and "fires" by flexing his thumb. Trevor apparently needs to make this gesture to use his power, as he was unable to defend himself when Sylar telekinetically pinned his hands to the wall.
These statesments are purely based on assumptions, it is not definitive that it needs to be "fired" for the ability to work. This could have been a gesture that he used to make his ability look more "cool". Maybe the ability originates from the index finger, and only needs to be aimed at the target (as we have seen Sylar do, on many occasions).
QUOTE (HeroesWiki)
Trevor had the ability of shattering, which allowed him break solid matter, although the full extent of his ability had not been seen he was able to shatter a solid glass whilst also making an attempt to use it upon Sylar.
All of the facts in HeroesWiki, about Trevor, are speculation at best (unless they have another source for their information).
Of course.. everything that I'm saying is also speculation, but that's pretty much all we can do right now, based on the information we have.