Tech companies may be different but every company I know has alcohol at holiday parties. Cab vouchers are generously provided and companies have people who monitor employees as they leave. Drinking on the job is something that has definitely changed. At one point (30 years ago maybe) it was pretty common to have drinks at lunch. Not anymore. I work with someone who worked in a beer factory when he was in college. They had coolers in the employee lounge with free beer for employees on breaks. Many would have one or two before they left for home at the end of their shift. Can you imagine a company doing that now?
She was on the phone bank, not some sort of job specialist. If they didn’t mind her getting packages at the office, fine. I don’t think she was drinking on the job. (At her level, I doubt there were any off-prem lunch invites from supervisors.) This isn’t a morals issue.
My law firm would throw amazing New Year’s Eve parties with open bar and free limo rides home to all, so most folks were dropped off at the party so they could go home in the free limo, which is that the firm publicized and STRONGLY encouraged.