You said “the DoD is the single largest consumer of fossil fuels” (emphasis mine). That is a very different claim than what the article says, which is that the DoD uses “more oil than any other institution in the world." Oil is just one type of fossil fuel; natural gas and coal are others. I would also contend that an institution is a very narrow class of consumer.

What you said is much more vague and could be reasonably interpreted to mean “the DoD uses more fossil fuels than the entire country of China,” which seems intuitively false.