Lighting a signal fire is usually a reasonable thing to do if you wish to signal for help. It is something that is taught at all wilderness survival courses. Signal flares are similarly used and taught as a reasonable tool. It is certain that these tools only make sense when there isn't a high risk of starting a wild fire. Putting aside the blame game for a moment and foregoing the discussion of the horrendous consequences to others of the wildfire, it isn't in the survival interests of a lost individual to immerse themselves in the middle of a wildfire.

The survival lesson I take from the actions of the person who used a signal fire / flare in this case is to think hard about what I am burning and where before lighting a fire for signalling or any other purpose in a tinder box.