in the old dub kaneda was still thinking testsuo was after his bike (which was originally suggested before any of the gang knew testsuo was buggin)
thats where his that comes from, he destroys yamas bike to aggressivly GIVE IT TO HIM (tetsuo)
He just crashed yamas bike instead of his because as you watched before, to recharge the laser battery they used the other dudes bike not his, because kanedas bike the coolest and you dont fuck with it