I really loved this video, and see it about four times complete. It is the second best video of Civil Protection in my opinion (I like more Aliens, since the humour there is priceless), and by far much better than any Freeman's Mind.
I think that Dave at the end is really speaking Bulgarian (Maybe mixed with some gibberish, but I think some Bulgarian must be there), and that they don't die. I see the hints on those two things at the start, the one being said directly (Dave knows Bulgarian) and the other with the car running over Dave... They start to compliment the body armor, and states that is REALLY good. Later, in the end, Mike keeps complaining during the credits about the monsters, but he didn't scream, or says that he is in pain. The most annoying things these creatures are doing to him is that "He can't even see". So, I think that he can survive this, thanks to his body armor, although I don't know how they can escape.
Another thing that says that they survived is the post from Ross Scott saying that this chapter really deserves a sequel. Since Civil Protection are these two characters only, if they didn't survive, a sequel couldn't be possible.
I really hopes that he can make a sequel for this, since the story seems really good to me.