That annoying beep shouldn't have been the only alarm for such a valuable and irreplaceable repository of decades-long research. There should have been an alarm system that issues email alerts to a chain of individuals.
If that annoying beep was indeed an overtemp alarm, then damage was being done even before the janitor flipped the ill-fated switch, and nobody was around to act upon the alarm.
Oh, no argument here. There definitely should have been a system to notify people not in the lab.
The beep might have been a reset alarm after a short power interruption, even if the freezer was working fine and hadn’t warmed significantly. I have a home CO detector that will beep loudly after a power outage until I reset it.