Gaming New Pokemon B(/W?) bug

[TheNikkoMan]

I was playing my Pokemon Black yesterday, and was training at the E4. I was fighting Marshal, specifically the HurrDuur thing (can't remember it's name). I used my Serperior, and both Pokemon were near faint. What makes everything so wierd is that after the HurrDurr used Hammer Arm, it lowered Serperior's health to 0. BUT! It didn't die! Rather it used Leaf Blade (like I told it to.. don't get the impression that it has a mind of its own) and killed it! I was like W0000T, but I was also so lucky that my Serperior went up a level, so I couldn't take a picture proving it..

Now I predict that a lot of you will call it bullshit, because I don't have any proof. But if you look at facts, why the hell would I do this if it hadn't happened? I haven't been trolling here (yet, lol). In fact I actually justfuckinggoogledit and found another case of the same: http://www.gamefaqs.com/boards/989552-poke...39189/626164507
I was playing on the real game card, but the Serperior came from a Black save on a DSTWO. Another thing to take into consideration is that the save on the real game card actually was started on (the same) DSTWO, but I transferred it over to the real game card to take advantage of the IR. I can't image what that would have to do with anything, and I haven't noticed any other wierdies.
The reason I actually took the 2 minutes and posted it here was so I could see if it has happened to anyone of you as well.