There is some conflicting things here, she had them on a watering system, or they had auto waterers (both things were mentioned in the comments). It was also mentioned that their was only one dead rabbit, and it was already a sick rabbit that belonged to a 4her that had it there being 'doctored', and the other dead rabbits were removed from the freezer (being sent to a wildlife place to feed other animals), but now we're hearing the dead ones were babies. So I honestly don't know.
What I do know is that 84 degrees does not sound that hot, it's hotter then that in my house, some of the comments also said the doors were left open for several hours before the temp was taken, implying it was actually much cooler before that. With that many rabbits it seems like the auto waters seem to make more sense, but I've never had to keep that many rabbits watered before either, so I don't know.
The conflicting info bothers me, makes it hard to know what to believe even when someone says they know this person.