I'm not 100% sure on this one, but I found a similar bug in the C++ source.
THe CurrentFlow variable wasn't being reset to CLEAR when a new bot began executing. The possible result of this could be bots that inherit the flow control from the previous bot that was executed.
For Instance:
Bot 1:
start
Bot 2:
10 .up store
The rules should prevent bot 2 from executing that store. Instead it's allowed because the CurrentFlow flag was still set to BODY.