Yes, that’s what he missed. Treeform uses a simple event-driven movement direction assignment.
self.accept( "a" , self.__setattr__,["strife",Left])
self.accept( "d" , self.__setattr__,["strife",Right] )
self.accept( "a-up" , self.__setattr__,["strife",Stop] )
self.accept( "d-up" , self.__setattr__,["strife",Stop] )It means, each “-up” event simply assigns zero movement vector, regardless of the first key down-state. So, you’d see this “feature” if you hold down A and D (or W and S) in sequence (not necessarily fast), then release one of them, and you’d stay still, since the key-release simply sets the movement vector to zero.
I guess he must intended to cut down the development time by using a simple vector assignment, rather than recording key-down states.