When they certify lights as “explosion proof” do they really test for battery explosion? To do that they’d literally have to have a battery explode inside the light and then check to see that the light contains the explosion … and stays sealed even with a massive amount of sustained pressure inside.
I’m doubtful that a light could contain an exploding lithium ion cell. The tube is 3mm at its thickest, but there are plenty of areas where the light is structurally weaker (threads, lens, etc.). Even if the tube survived an 0-ring giving out during an explosion might be enough to ignite a spark.