No company knows to reach out without the customer contacting them. I fully acknowledge that this guy has done that, but in all the companies to which I have sent firearms in for repair unless I contacted them and kept contacting them they wouldn't respond. The onus, and this is not me saying this is fair, is on you.
You state this as taking 9 months (though in the video it's April til December, which is 8 months and he didn't start contacting SIG until July). SIG returned on their dime the pistol and sent him back the pistol with a new barrel in 12 days from the original phone call. Then per him that barrel had similar issues. He contacted SIG again, had to email a form, then became frustrated when in 3 hr he hadn't gotten a response to that form, called again, then did get a return letter at end of day. At multiple points in this video the gentleman mentions how he had sent them links to the videos and no doubt they were mad because they had watched the negative videos and that's why he didn't get a response until the end of the day (rather than the seemingly more likely reason being they were busy).
This gentleman has 33.8k subscribers, which is 33.8k more than myself, but I'll be honest and say that I don't see how that matters and there seems to be an attempt from what this man describes to exert some additional leverage against SIG by suggesting more bad press if this isn't resolved. I'm of the opinion customer service should treat you the same if you have 33.8k subscribers or 0 subscribers. Having a YouTube channel doesn't make you special or skip everyone else having issues themselves. He's not the only person with whom SIG is dealing.
He then doesn't get a response by 9/8 and starts calling and recording his interactions. He speaks to someone he admits was polite who admits the pistol is still in process and SIG doesn't have a solution as of yet. When he does get the pistol back again in a month or so he makes the point in the video how they note on the repair form that he had YouTube videos on the pistol, which to him is proof they are "mad as hornets and can't stand him calling them out and they're getting an attitude about it." Or it could be them acknowledging something that he specifically admits to making a point to tell them when he called before. He is then mad that they report rear sight damage and seems to regard it as lying, when frankly firearms can get damaged in shipping or in the factory itself as it makes it's way to the tech doing the service (especially as the rear sight is polymer in this case). SIG never appears to claim the rear sight was the cause of the issues he experienced, so I don't quite see the concern.
At this point in the video he's angry and getting visibly upset. He admits to pulling the "YouTuber card", which goes to my earlier point of how I personally find that objectionable, and promising SIG more bad YouTube videos that will be seen by "tens of thousands of viewers" if he doesn't get a refund. In the end they agree to refund the pistol, he sends it in, they inform him it may take multiple weeks for the refund to be issued. Two months go by, an admittedly long time (I agree with him that it's too long), he doesn't receive the check, then emails them. He gets a response saying the check was misplaced and they will mail him a new one in a week. The fact that the check could be sent that fast this time is apparently evidence to the creator of them lying the first time because they were mad at him because of his videos and so deliberately did not send or delayed sending him the check (the creator says the service rep is a "mad little liar"). This seemingly ignores that in times customer service will expedite certain requests to try help a customer out. SIG trying to be faster to respond becomes a bad thing.
The letter then gets destroyed, admittedly by the USPS per a cover envelope from them (although he does ask "if it was the post office..." in the video). He ends the video saying he will never buy another SIG and that the P322 is "absolutely terrible, every single one of them" and has leading issues (I guess those of us here who haven't had bad luck are in denial). He states that SIG as a company is "absolute trash" and everyone he dealt with is either a "liar or completely incompetent". This seems disingenuous to me, as he mentions two customer service reps by name with which he mentions having good experiences.
I think everyone is entitled to an opinion. Do I think this gentleman was completely reasonable? Honestly, no, even though I am willing to believe the P322 may well have/had production issues. Why do I care? That's a fair question. My wife worked customer service for a number of years. The number of people that would call and be rude to her, including swearing at her, insulting her, and even threatening her life on occasion, was mind blowing to me and I've seen that attitude all over the place. More often than not that behavior was unnecessary and counter-productive. So do I always believe the customer over the company? Not anymore and this video doesn't seem objective to me. YMMV.