If it leaks, it won’t damage much!
I’m sorry, but the photos and information lack sufficient information to comment on. Even with the most detailed information, it is a WAG (wild a$$ guess at best).
You where there, what is your impressions?
If you saw a hazard, go with that. The client’s concern is the only concern. It does not have to be fixed, the property doesn’t have to be purchased.
The Mfg’s installation manuals for the equipment you are looking at.
Carrier Blue book etc. covers many standard practices.
HVAC is an area that is mostly outside the scope of HI.
90% are not installed 100% correct.
100% have failure after the inspection.
If it were me, I would keep away from as much HVAC as I could until I got
a firm grip on the subject.
If the client has concerns, he/she should consult with an HVAC contractor/engineer.
*If **you do not have the education, provide where the information can be obtained. It is not your job to know everything, just where to find it. *