I know you have the "employment at will" thing in the USA (I have no idea how MA state law would interfere), but I'd be a bit surprised if this was a one-strike-and-you're-out matter. The boss could argue that asking a co-worker to take their top off would be sexual harassment, or "creating a hostile workplace", I suppose, but considering the shenanigans people get up to in the workplace in QCverse all the time, I can't see it happening.
If it's a larger corporation and the offender is any less than an executive, insta-firing for sexual harassment accusations is actually quite common, even in states that don't have at-will employment.
Ultimately, the worst that will happen if an employer fires someone on an accusation is that, if a judge rules in an unemployment hearing that the firing was without valid cause, unemployment compensation (and potentially back pay in a state that doesn't have at-will employment) will be provided to the former employee, and unemployment insurance rates for the employer will go up slightly. And, on a sexual harassment accusation, that would almost always be found to be a termination with cause.
Conversely, if they
don't fire on the first accusation, they're opening themselves up to liability for creating an unsafe work environment, which could cost them millions in a sexual harassment lawsuit.
As far as smaller employers go, there's less institutional knowledge on the correct responses to sexual harassment, there's less bureaucracy (no formal HR department) to use against a harasser, and there's more likelihood that the harasser is a higher-up in the company (which in
any company is more likely to result in no action taken, because a higher-up has more ability to stop the investigation or firing, and because the company values the higher-up more). And, note that many of the workplaces shown in QC have been smaller employers...
And then, food service is another level worse than small employers in general (even - maybe even
especially - when it's megacorp food service, due to how those are structured), as I understand - a lot of workers in food service don't know their rights in this regard, there's no HR department to go to, and sexual harassment also comes from the
customers.