I've been doing some testing on a mamba 25 5s, blew it also. Extended part throttle operation seems to be about the worst thing you can do to that controller, especialy on 5s. I did test full reverse-full gas-full-reverse back and forth 4ft. passes up to 4 passes to heat up controller. Continuos 2cnd gear full throttle runs (in grass geared high enough I had to take of in 1st then shift to 2cnd) didn't heat it up enough to worry about. However something that doesn't apear to be abusive (extended part throttle runs) really put the heat to it. Higher voltage made it happen even quicker, and gearing down so as 5s top speed matches 4s top speed didn't help either. This test with a fresh pack killed my speedo quick (20-30ft at very low throttle input).

The m.m. manual even stresses gear down don't cut back throttle end points.

I know the m.m. is a much diffrent controller than the 25, but imagine they have the same tendancys.

Is there any chance it went puff because your wife was trying to take it easy on the truck? If this looks like a possible cause to you, it might save some other peoples controllers to keep this in mind.