My wife went from a 2001 Grand Caravan to an 08 Nitro, our other car is an 07 Charger R/T for refernece.

The Nitro takes some getting used to the Brake is a little mushy - you have to exert more force then youdo with the Caravan or my Charger.

We haven't had any problems with the Nitro but every time I get in to drive the first Stop sign reminds me I need to push harder on the brakes to get it to stop.

For your story my bet is your wife hit the gas and it was an accident or started with the brake and slipped to the gas when it started moving forward on her.Yeah its pure conjecture but a problem like you have reported is a pretty big deal, if it has happened to others there would be a recall or at least other reports.

I don't know you or your wife from Adam, but with what you have posted of your actions I am betting it was far easier for your wife to tell you the car jumped uncontrollably versus telling you she ran into the house because she wasn't paying attention and her foot slipped from the brake to the Gas pedal

But thats just my 2 cents