I wonder what the outcome might have been had there been no engineer on the tarmac to alert the crew to the situation?
Dare say that this incident will not factor into the bean counters reckoning when they next look for an area to cut costs. LAME-less tarmac's are unfortunately still on the wish list of airline management.
But that's probably for another thread. Just glad that nobody was seriously injured and that there was no smoking hole left in the ground.