West Coast's Andrew Gaff punched Fremantle's Andrew Brayshaw in the face, breaking his jaw and "caving in" the teenager's teeth.

These are the only facts that really matter, the only facts the tribunal will take into consideration when it likely ends Gaff's season on Tuesday night, and the only facts history will record of an act of violence not seen in the AFL in a decade.

But the reaction to Gaff's hit and Brayshaw's injuries have been even more visceral than usual. Those watching live moved from shock to disgust to anger in record time, as the football match descended into farce and the on-field melees spilled over into heated Twitter spats among fans.

There's good reason for the heightened emotion though, and it all comes back to the history of both players involved — the victim Brayshaw, and the perpetrator Gaff.

Andrew Brayshaw will be unable to eat solid food for four weeks after the punch from Gaff. ( AAP: Richard Wainwright )

Firstly, and most importantly, Andrew Brayshaw. The second pick in last year's draft, a young footballer of immense potential who was enjoying a strong debut season with the Dockers and, from all reports, a high-quality young man.

He comes from a family of footballers and, unfortunately, a family whose entire football experience in recent years has been wracked with anxiety and fear. Specifically because of injuries to the head.

Andrew's older brother Angus is 22 years old, and was drafted at pick three by Melbourne in the 2014 draft. His fledgling career with the Demons has been threatened, time and again, by repeated concussions.

He has spent considerable time out of the game recovering from knocks to the head — four concussions in 12 months, to be exact — and only this year made a tentative, helmet-clad but so-far-successful return to the game.

Angus Brayshaw's career was in jeopardy after suffering four concussions in one year. ( AAP: Tracey Nearmy )

Angus's plight has put considerable strain on the Brayshaw family, with his mother Debra revealing last year she had to undergo hypnotherapy to even be able to watch her sons play football without overwhelming nervousness and anxiety.

Ms Brayshaw was in tears in the changerooms with her son on Sunday afternoon, before he was taken to hospital to undergo surgery on a broken jaw.

It's a heartbreaking story for her and the entire Brayshaw family — including brother Hamish who, in what will surely lead to some beyond awkward and potentially confrontational discussions on the training track, plays with Gaff for West Coast.

For any footballer to be the victim of such a horrific blow would be horrible, but for it to be Andrew Brayshaw seems particularly cruel, and adds yet another layer of darkness to an already terrible act.

Gaff's indefensible strike comes out of the blue

And then there's Gaff.

Since letting loose with that devastating haymaker at Perth Stadium, you probably would have heard how, "out of character" this act was for Gaff, and how he is, "the last player you would expect" would be capable of something like it.

Like it or not, this punch can no longer be considered "out of character" for Andrew Gaff. ( AAP: Richard Wainwright )

While true — Gaff has never, in his near-200 games of AFL football, come close to something as horrifying as this — it is not an observation designed to exonerate Gaff, but rather to further illustrate just how once-unfathomably shocking the spontaneous explosion of violence was.

Gaff himself has offered no explanation for his actions — and would be well advised to keep it that way, as there can be no acceptable excuse — but instead only sincere apology. Even he seems shocked and appalled at himself, he too questioning his own character just as we have been forced to reassess.

It all contributed to a quite ridiculous afternoon at the football, where vigilante justice was the order of the day and a home crowd short on details but fuelled by desire to instinctively support their man rallied behind the aggressor.

There was something deeply unsettling about seeing the Eagles' side gather around Gaff in defiance and celebration after the Eagle kicked a fourth-quarter goal, but what was most telling was the reaction of Gaff himself. His face blank, drenched in guilt and shame, he was the only person in blue and gold who really seemed to appreciate the weight of his actions.

The game turned into a spiteful scrap after the flashpoint on the wing. ( AAP: Richard Wainwright )

The repercussions for Gaff will be severe. His suspension will, at the very least, see him miss the end of the season and quite possibly a chunk of the next. No suspension could really seem too harsh.

He is currently at the centre of a league-wide bidding war, with million-dollar contracts on offer from clubs around the country desperate for him to don their colours. How this act will affect negotiations remains to be seen, but there's no question Gaff cannot be considered the same player he was on Sunday morning.

His absence will almost certainly end West Coast's hopes of challenging Richmond for a premiership, a point that matters little in the scheme of things but ensures the punishment of the player is significant enough to severely damage the team.

Gaff was targeted by Fremantle players after the punch, and offered little by way of resistance. ( AAP: Richard Wainwright )

More than anything, Gaff will wear this act next to his name for the rest of his career. By definition, it can no longer be considered "out of character", and that's something even the most genuine of apologies can't change.

But while he wakes up with little more than a besmirched reputation, Brayshaw does so in hospital, probably in immense pain, surrounded by fearful family who have seen far too much of this already.

There's no question who is suffering most.