Not sure that the SP would not have fallen either way. Horrible Playbook launch. Many delays for new smartphones. Lost overall market (and especially North American) share. Looking foward, RIM prospects were not looking so great.
No one was really certain when the new BB10s would come out. Even if they would be good. Stock market is a scary place to be when you're uncertain.
I'm also thankful for the buying opportunity. I would never have bought RIM if it wasn't a third of it's Book Value. Now I can't see myself selling for a long time.