I know it's too much to expect people to RTFA, but as others have pointed out it would take much more than 1 mutation. The main point the "doom and gloomers" are missing is that these modifications are designed to complement existing containment techniques.
Think of it as a potential way for researchers to more safely work with deadly bacterium such as anthrax. They would still use all of the traditional containment methods, but have an additional fail-safe built in. Ultimately these researchers hope to come up with multiple overlapping safeguards to provide even better safety.
It's beyond me, how anyone could object to making it harder for bacteria to escape from the lab!!
Besides, I've never understood this objection. We already know about neutrinos which have mass and are weakly interacting (they only interact via the weak force and gravity) . A dark matter particle could be very similar to a neutrino, except it would not interact via the weak force and would likely be more massive.
http://en.wikipedia.org/wiki/Percy_Schmeiser says that:
"He testified that he then harvested that crop, saved it separately from his other harvest, and intentionally planted it in 1998"
So perhaps you could use your superior search engine skills to find an actual, real example of a farmer being sued by Monsanto that did not intentionally harvest and plant patented seeds?