Frequently if the dog fence is not working the problem either lies in the training or the collar is not making proper contact with the dog's neck. (dogfencediy.com)
Finally, if your car does also have the second type of neutral switch at the transmission, by rolling the car you may somehow be allowing that switch to make proper contact again. (mechanics.stackexchange.com)
If it's too big, the oil in the egg will not come in proper contact and the emotion won't happen. (theviewfromgreatisland.com)