The rules for it say that it just provides armour points for everything. While this makes sense with most weapons (Bullets can be deflected, blades ditto, power weapons the same, even a flamer blast you could redirect the fuel stream), with las weapons it doesn't really work. What on earth is the telekinesis deflecting? For that matter, how does it stop plasma and melta shots, which are basically really superheated gas? I mean if they stop gas coming in, then the caster will run out of air.
In short, should I play this scientifically, or come up with some stupid reason why the rules work?