Yep, if your house was filled with gas, a minute spark from the doorbell button or mechanism could set it off. Just a standard policy practice.
We knew a young man who was renting a condo in Las Vegas, while attending UNLV. He entered the condo and flipped on the light switch and the whole place blew up.
There were no gas appliances in his condo, but other condos did have gas. The leak was in the wall.