Couple of points.

It's never gone past 600 degrees before and always after I put food on it drops to about 500.

There was no alcohol, I don't drink.

When I say I walked away, I mean probably 10 steps around the grill to turn on a fan, we grill in the shop out of the wind.  It was about a minute and a half after I flipped the steaks that he saw the flames.

The grill has worked great prior to this.  We had some pork sirloins on it a couple of weeks ago and at that time I left them on for about 2 minutes a side, turned the heat down and put them up on the top rack for another 10 minutes, after which we ate juicy pork sirloins.

I'm going to clean the grill and try it again next week.

Glad I could allow some to have a laugh.