This happens because of the order of events when drawing a move:
When a Move is completed, it turns blue, however, it is not added to the combinatorial representation (to the current Graph)
Then the game waits for the user to click on the highlighted Move to select the middle sprout
The middle sprout splits the Move from (1.) into two Moves and adds them to the combinatorial
representation. If a sprout, which was added in (2.), is too close to or if it intesersects the cobweb, the game will not detect the intersection and the cobweb will not be torn.
Bug in v.0.8.0