I think it's important to point out that the FD crew don't have the benefit of hindsight; they can only make the best call that they can with the info they have available.
For all we know they might have had reason to THINK fuel was pooling under the aircraft (regardless of whether it was or wasn't) and thus may have felt that in that situation they were better off to sit tight until rescue services were in a better position to protect them if they evacuated into it.
Who knows? THEY DO - We don't. And it's not fair to judge them until we do.