2012 LEXUS IS Engine Problems

While stopped at a stop light vehicle RPM went very high. It reached the red zone. Vehicle started moving forward (while still on Drive and the brake pedal fully pressed). I immediately put the vehicle in Park. RPM continued to remain high. I removed my foot off the brake when the vehicle was in park. I turned the engine off, waited couple of seconds and turned it back on. At that point everything worked normally. Outside temperature was about 38 deg F. Car was not fully warmed up at the time. Floor mat had nothing to do with this incident. After restarting the engine it is working fine without any adjustment to the floor mat. Incident could have resulted in major crash or injury. Luckily it happened when the vehicle was stopped at at red light. Putting the car in PARK and turning off the engine resolved the issue. This...