I wouldn't mind so much if it was a trick I could use as well, but no such luck. Another thing I saw recently was a player who attacked and instead of leaving the minimum 3 troops, he was able to leave only one and then continue attacking in a different direction.
about 1 month ago
I've noticed this too and its very annoying. AI players have always been able to do that (which I think is lame) but human players is definitely not ok.