Software problems of the 2008 Toyota Avalon

My wife was turning off sunrise highway (westbound) onto the wellwood Ave ramp.   for some unknown reason the engine started to rev very high.   she try to stop, using the brakes, but the vehicle would not stop.   she then put it into park and the vehicle stopped.   while stopped another vehicle hit her in the rear.   the main problem here is why did the vehicle's engine start to rev up.   when I got to the scene there was a police office there.   both he and I checked the car, I got in, he outside, and when we started the vehicle the tach show ~950rpm.   I look at the floor mat and it was in place.   the vehicle was towed to Toyota.   a rep from Toyota called my home and spoke to my wife.   his very first question to her was do you have other manufacturer's mats in the car.   she answered no, the came from Toyota.   he then proceeded to explain how nothing could be wrong with the vehicle.   when he went to Toyota to inspect the vehicle he determine the corner of the mat must have been stuck under the gas pedal.   I do not believe this is a fair inspection since he said this same thing before he ever saw the vehicle and when the police office and I checked the vehicle the mat was in place.   I do not know if there is a problem with the vehicle but I do know that I do not believe Toyota gave it a fair and impartial inspection.   also another Toyota representative call my home and implied we were trying to get our deductible from Toyota.   it is remarks like this that make me questions their findings.   I don't want anything except the knowledge that he vehicle is safe neither I nor anyone else will experience this problem again.