In Hatchet, how does Brian's first bow nearly spell disaster for him?

In Gary Paulsen's Hatchet, Brian's
first bow nearly spells disaster for him because when he tries to test it, the bow wood
explodes in his hands, sending deadly splinters and wood chips into his face. Two sharp
pieces actually lodge in Brian's forehead, just above his eyes; had they landed slightly
lower, they would have blinded him, inflicting a devastating injury that would have
seriously compromised his ability to survive (Chapter
13).

Brian had actually made a previous attempt
at fashioning a bow, but before he had gotten very far along, that attempt too had
almost ended in disaster, because it triggered a series of events that very nearly
caused him to give up hope. In that incident, Brian had carefully chosen a branch with
"an almost vicious snap" to it to make a bow. The wood was hard, and he had been
concentrating so intently on carving it correctly that he had not at first heard the
"persistent whine" of a passing plane. When Brian had finally become aware that rescue
might potentially be near, he had thrown down his bow and run to light his signal fire
as fast as he could, but just when he had finally gotten the flame to feed, the plane
had turned and disappeared. Brian had been so devastated by this event that he had given
up hope of ever being saved, and had gone so far as to try to kill
himself.

Brian was eventually successful in making a
serviceable bow, but both of his early attempts were unsuccessful and dangerous. The
author says that Brian's first bow "was a disaster that almost blinded him," and this
turns out to be true both literally, when it almost causes him to lose his physical
sight, and metaphorically, when it nearly causes him to lose sight of his determination
and resolve (Chapters 12-13).