Foundation inspection question

[Adam Rey]

Have a house under contract that during the general inspection it was recommended to have a foundation engineer inspect the foundation because of some cracking inside above doors and walls that could mean the foundation is shifting or settling. The engineer inspected the exterior foundation and thought it looked okay. However he said the current owners wouldn’t let him look inside even though he repeatedly ask, and so the inspector wasn’t totally comfortable with the condition since he couldn’t inspect the indoor cracking above some doors and walls. My agent says he hasn’t seen this before but worries it means they’re hiding something. They let the general inspector inside but won’t give a reason why they didn’t let the foundation inspector inside. Anyone have any thoughts? Even the experts are telling me they aren’t sure.