This IS the final validation step. Going live is the final validation.
Heck they might have installed it on a Windows PC. It’s so easy to get false positives in your controlled test environments. Your team puts some “helping” apps on the test machines and it turns out your software actually relies on them. A hardcoded path to something on your network. Heck even a “proper” clean machine, then you’re not getting potential conflicts from junk like Norton.
Especially in the hurry up and ship constant update model. With razor thin staffing. Probably your QA department says they need 6 months to do a proper regression, but you slam out updates every couple weeks.
It’s not like this is new. I think this is the 3rd or 4th major internet crash this year. Only way it stops is if the business world moves from demanding fast updates to stable updates. Then updates won’t come out more than once a year and real testing can happen. But it also means found problems stick around for months.
Yup, been there done that. You'd have thought that they (and we) would have learned.
BTW, do not install this kind of software on your home PC... Norton, Mcafee, etc. Bad, very bad!