Only thing I can figure is that the cable is loose where it pulls the catch, or the white collar has come loose and the cable is moving. I just changed my carrier yesterday, here's a thought...

Pop the oval grommet off of the door jam. Remove the hex head bolt (see carrier DIY). Pry the cover off of the lock on the outside handle. There are two retaining tabs - top center and bottom center of the cover. Gently pry on either side of those, or pull the handle out and start on that side. As I type this, I'm realizing the cover may come off with the whole lock...meaning no need to remove cover separately. Once cover and hex bolt are out, the lock mechanism can be pulled out (toward outside of door, had to pry mine a tad bit). Then you should be able to see the cable that pulls on the latch. You might be as to release the door by pulling the cable with pliers if the carrier mechanism is broken. Or, if the cable collar or ball socket are broken, you might be able to get a coat hanger or something similar on the latch lever and lift it up to release.