to be fair, had authorities intervened and taken the guns away, many 2nd amendment enthusiasts would have been all over it and complained about the unreasonable overreach by the tyrannical government.
concerning your first scenario, it's hard to say. i mean, reason and logic tell us that the chance of him going through would have been smaller had he remained in treatment, but obviously that doesn't outright prevent it.

it's really a shitty situation, and as long as there is not massive abuse or negligence on the parents' side, it's really hard to establish a direct responsibility. i mean, it's hard to not sympathise for and understand where both sides are coming from here, it's just tragic that with all that talk about mental health being the REAL culprit, not even such obvious potential threats are covered - it's almost like all that concern about it primarily serves as an excuse, and not as an area for political action...

imo what we have here is a simple equation. guns + mental health problems = tragedies. subtract either and you wont get the same end result. and the problem comes in how to subtract either. full mental health coverage isn't realistic to expect and full removal of guns is all but impossible. so we're slowly slowly slowly trying to play advanced algebra to come up with a better equation. democrats want to see if (less guns sold + mental health problems) come out to the same result. republicans are only really willing to point out the mental health side without much policy proposed to combat the underlying problem. perhaps the GOP Is taking the view that mental health problems are as unsolvable as they believe the gun problem to be.

what would be a good idea is bolstering the child protective services. my wife has a child who's a 4 year old autistic girl with a 6 year old autistic brother. the mother has documented and severe social anxieties that extends to her kids. so for their whole lives she put them in a room with a TV and maintained minimum contact. the brother started to physically abuse the sister. she's got trauma stacked on trauma with no emotional anchor in sight. she comes to school with bruises, and is by all accounts not ever going to make progress because the trauma runs so deep. CPS has been called dozens of times, no official action other than home visits and lectures. these kind of negligent environments imo are what creates shooters, not that exact environment but a congruent level of trauma and lack of emotional support.

god wearing a MAGA hat. people really are fucking gross. the meme works fine without it, the addition is blasphemy.

The lack of self-awareness here is astonishing.

always thought it was stupid to pretend it's a single angle issue, or to act like it could be solved by focusing exclusively on one aspect. that said, mental health is a problem that exists to similar degrees in america's peer countries, and it's also something that's much harder to qualify in legal terms, which makes it significantly more difficult to introduce effective legislation for. cases like this, where the individual already passed the most important and difficult hurdle, and sought professional help, but had to abandon treatment because healthcare didn't cover it, are therefore particularly tragic imo - even without the subsequent shooting btw.

the 2 things i'd add:

1. both sides are a bit to blame for the false dichotomy. when u mention mental health a democrat calls it deflection, same when a democrat mentions guns.

2. in the same way that mental health is hard to legislate in Europe gun laws are hard to legislate in the USA. that pesky 2a and the founding fathers making a system where the constitution is above all other law...

we're coming to a point where they amend or remove 2A. be it 10 years or 100. its coming. and i think that explains a lot of gun nut's "take it from my cold dead hands" attitude, they think it's 10 years rather than 100.

it's a difference if you only pretend to care about mental health after another shooting, or if you're somewhat principled on the issue and work on it when it doesn't just serve the purpose of deflecting from guns.