1-Some of the guests' belongings were destroyed in the fire.
Can't this sentence mean two things:
1a-Some of the belongings of the guests were destroyed in the fire.
1b-The belongings of some of the guests were destroyed in the fire.
(It seems to me that in this case some guests have lost all their belongings, while others have lost none.)
Do we have the same ambiguity here:
2-Some of the patients' behavior was strange.
Two possible meanings:
2a-Some of the behavior of the patients was strange.
2b-The behavior of some of them was strange.
Yes, they are ambiguous.