Great research with the flare artifacts Joe.
Whilst the flare might have been used attempting to attract attention, start a fire, illumination, anti-crab defense, gone off accidentally, is it possible, rather sadly, when life was almost gone might it have been a final deed?
When Joe mentioned the foil artifact was difficult to flatten, it gave thought to ‘why‘. It seems to be a fragment that one might expect to be internally burnt & blacked, yes; but why so badly distorted and seemingly violently ruptured, particularly if it was from a (blue) hand-held type? Who would want to ignite a flare expecting it to disintegrate or explode? Might this artifact be so distorted due to unsuitable deployment? Possibly ignited in a confined space (a box), perhaps if it became wet within? Or held against something (a crab, flesh), though not oxygen excluding, possibly causing excessive temperature and particularly high internal structure-destroying pressure, aka, catastrophic failure?