I agree, if you can't quarantine them in a separate room, don't do it. That said, if you CAN quarantine them in a separate room, and none of them show any outward signs of illness, I would do it in a heartbeat.
The deaths of the hatchlings could have been due to long-term neglect by the suicidal owner, culminating in simply NOT being fed since his death. That's all it would take to have the hatchlings all die.
If any of the animals show signs of RI or other issues, however, I wouldn't touch them.