First, you are replying to do different comments. The op described the smell and it wasn't the smell of gas combustion. Complete combustion doesn't smell, most of the smell you get from burning gas, is not a gas combustion product, it is unburned gas and odors from the parts that get hot.
If you want to talk about meaningful numbers of deaths and injuries try talking about falling down in the bathroom. People die. However, accidents cause relatively few deaths, and accidents where a person did not do something really stupid such as drive drunk, not look first, not put the draino where the kid couldn't reach it, etc. result in very few deaths statistically. Most people die of heart disease. If they really cared, they wouldn't smoke, they would stop eating 2000 more calories per day than they burn, quit drinking 12 beers each night. The statistics say that CO deaths are practically non existent. As an individual precaution it makes sense, but as advice to another it is a wasted of time. They are going to die of something else.