Wow!! That sure Popped!
My neighbor lived through a propane explosion in a camper once, but he was pretty crispy to say the least.
I remember my metalwork teacher filling a paper bag for 2 seconds with acetylene, and letting it sit, then showing us how it would still go boom. He also showed us a film that said that acetylene bottles are special because of the properties of the gas, you cant just compress it a lot, or it will explode. the cylinders have to be filled with a special stuff that lets the acetylene compress beyond about 35 lbs, to hundreds of pounds, with out exploding. Anyways, cool pix, thanks for the share.
A)It's an enclosed vehicle. He shouldn't be transporting a tank in it.
B)The tank didn't have a cap/collar by the sound of it.
He should consider him self lucky his stupidity didn't kill him. Both of these are clear violations of transport regulations for tanks. You wouldn't be allowed to leave the property with a tank larger than a grille tank of flammable gas in an enclosed vehicle when I worked for a propane company.