The Wonderland Board

so i was exploring the sewers at the lowest level and used the spy eye and i noticed a thwart's hand sticking out of the door where the entrance to the level to catch a thief was. the same thing is also visible at the beginning of the level introducing wysp from the door where the thwart came out of and stole the blue shard. why does this occur

That's just how the models are. The thwarts are fine, don't worry!

but how would models explain why a hand would stick out of a door

The thwarts are never deactivated.
Their move path just ends them in fake walls without deactivating them. The fake wall will usually cover them up,
but some models, like the thwarts, are bigger then the standard tile width/length, so you can see them if they are in certain orientations.