Bulging cans

My wife noticed that one of our food storage cans was bulging. My first thought is, well, we should throw it away. Then I started wondering, how can muffin mix get botulism? Doesn't botulism need water for its growth? So I checked with the company that sold it to me. 3 year old muffin mix (and mine is 3 years old) can sometimes have a problem with the leavener inside activating, thus creating gasses that bulge the can. According to them it is still safe to eat, but we should use it up soon. And add a bit more leavener to help it rise, since the leavener that has already activated is no good.
Just thought that I would post that as a public service announcement.

Isn't that interesting! That's a new one on me. Thanks!