Automatic Transmission Gear Indicator problems of the 2003 Nissan Sentra

On may 15, traveling together on a side street at 30-35 mph, my wife inadvertently tapped the shifter. The transmission immediately went from drive into neutral. there was no immediate danger at that time as there was no car behind me, and I was traveling fairly slowly. I moved the shifter back into drive and continued home. The more I thought about this event, the more worried I became. Supposing I had been traveling at 70 mph, in the passing lane, with a truck bearing down on my rear? if the car suddenly went from drive into neutral, it would immediately begin a drastic slowdown, and no brake lights would come on! by the time I got it back into gear and the truck driver figured out I was stopping dead in front of him, his truck could literally be on top of my car. On may 19, I took the car in for a regularly scheduled maintenance at the dealership. Prior to that I held a test and found that I could also move the car from neutral into drive without depressing the button! the danger in this is obvious, especially for any owner with small children. I told the service advisor the entire story, and my concerns were added to the work order. When my car was returned, I was told this is the way the car is designed. I have this in writing on the work order. I went to the Nissan web-site and told customer service about my problem. Their answer was they do not have access to technical information and I should call or visit your local Nissan dealership. I also have this e-mail saved. A manufacturer designs a transmission which would allow a light tap on the shifter to result in moving from drive into neutral and vice versa? and then, when confronted with a dangerous situation, says, well, thats the way it is! this needs to be corrected before a tragedy occurs.