Yeah, totally on purpose. This was a long time ago and mental health wasn't taken as seriously as it is now. Today it would have been called PTSD and he would have gotten help had he been born 20 years later.
You know poison control hotlines? EMTs on the scene had to call them for advise. So if the local poison control center doesn't know the answer right away, they have to call the next higher one which is like for the eastern half of the USA. They didn't know either and had to call up to the one which was in charge of the whole country.
Poison control toxicologists move fast. They know alot and have alot of resources on hand in case they dont. I guess this was one of the first times they had ever heard of ingestion of chemicals from a fire extinguisher in the country.
By the time it got up to national level, which was only a few minutes, the guy was gone. Autopsy basically showed the dudes lung was stone. Everything down to alevoli was filled completely.
Damn right there are better ways. Must have been scary as hell for everyone.