Yes, any walls that bow, especially horizontal, need to be looked at by an engineer. Remember you are there to identify any problems, and call in the expert to quantify the issue, and recommend a fix.
Sounds like your boss works for the realtor, not the clients best interests.
I understand his position, of wanting to keep business going, however it's your ethical call.
No picture showed itself.
Certified, American Society of Home Inspectors, local chapter board member, and Mentor. Director of education, and 25years building contractor.