Ok, assuming that it is agreed that adding oxygen to a fuel fire will greatly accelerate the combustion - far more than adding an equivalent amount of fuel, how about this?
The oxygen tanks upon being overheated, burst simply because the pressure limits of the tank were exceeded. Then, immediately, a humongous amount of oxygen is added to whatever fuel is already burning.
I cannot imagine that the addition of this much oxygen so suddenly to an existing fueled fire - along with the “explosion” of the bursting tank - would not simulate an explosion.
This is why liquid oxygen is used to control the rockets in the shuttle - if it were not controlled, one would have an explosion - from the oxygen accelerating the combustion of the fuel. The rocket is in essence a controlled explosion. Most of the time. Let’s do some research on what happens when liquid oxygen tanks have burst open on a failed rocket launch. I’ll bet what happened was an explosion.
Never heard of this scenario being reproduced. Maybe Mythbusters could do it.
WHY do you even think oxygen tanks were on the truck?