Oxygen tanks do not explode when near an ignition source like Rita's cigarette. The oxygen would just make whatever is burning burn much faster.
The kid's grandfather is called "The Colonel", yet he is wearing the uniform of a US Navy Captain. A Captain in the Navy is the equivalent pay-grade as an Army/Marine/Air Force Colonel (O-6), but they are not the same rank.
E. J. Callahan's character is referred to as "Colonel" , but at the birthday party he is wearing the uniform of a U.S. Navy Captain.