"Oooh, what the fuck?!"
So it looks like you ejected the squib case, then tried to chamber another round and fire, but the new round wouldn't chamber all the way because the squib bullet was stuck at the end of the chamber. Is that correct?
If so . . . as you know, you got lucky. If the squib bullet had moved just a little farther, you'd have had a real problem.
I've gotten similarly lucky in the past.