Re:Nope, it happens in plenty of places (Score 1)

Lots of good information. The examples on CandlePowerForums are all of 2xCR123 configuration, There seem to be a number of Pelican M6 plus an assortment of others including Surefire and Goldston and a range of battery brands. There are a number of folks over there who have been trying to replicate the problem with mixed success, seems the issue is far more prevalent in units where the state of charge is mismatched, that is one cell at 100% and the other at something like 40% in generally hot conditions. There is speculation of some reverse changing issue as well as it seems that the 100% cells are the ones than tend to vent. You also identified that these are usually occurring on Xenon type lights where the draw on the cells is extremely high. So far we have yet to see an example of a single cell light or a LED light (most draw less current through a regulated driver of some sort) causing this problem.

So really for the Lithium primary problem in flashlights it seems to be limited to a set of pretty specific circumstances.

It is still possible for these batteries to explosively vent if damaged. There was a fire at LAX when a forklift punctured a container load of these things and of course some other folks are selling safer chemistries and using this demo video to reinforce their claims:

http://www.a123systems.com/html/tech/safety.html

You are right though, careful design perhaps was not always done with some of the cheaper lights.