He wouldn’t have “took the risk” like you think. He wouldn’t have thought “I’ve only got a few minutes but I’ll give it a go”, that’s not what people are concluding.
what the conclusion is talking about is that he believed the indications to be false, hence he continued to fly. The task is irrelevant here. The sheriff agreed with many of us that he believed (wrongly) that he had loads of fuel. Trust me, my first reaction was exactly that.