You should clearly define what you are inspecting and what is excluded. This includes levels or methods of access and inspection such as adjunctive equipment or instruments. Then, once your scope is clearly defined, you are accountable to that scope according to your local Standard of Care within your industry.
The test is, what would a reasonable and prudent inspector observe and report under simillar circumstances? This does not mean you have to meet a Mil-Spec, issue a NIST certification or UL listing nor does it allow you to claim glaucoma or your stiff back from preventing accessing and visualizing something. If any reasonably physically capable inspector can get to it using the level of access defined or provided, then it should be reported.

For instance, no inspector would be asked to access a 14/12 slate roof but if your contract with the client stipulates they will have a hydraulic lift platform sufficient to access all portions of the roof within X# of feet and you are being compensated for this additional level of access or adjuncts, then yes, you would be reponsible for conditions there. You would not be responsible for inaccessible areas such as an encapsulated attic unless they cut a suitable access hatch that you can reach with one of your ordinary ladders or they provide one to your specs.

Regardless of such verbiage as in the OP, the ultimate test of course, is in court.

You manage expectations by a comprehensive contract. Now, your contract should evolve. As you encounter situations or expectation conflicts, you should capture that info. then bake a resolution to it in your newly revised contract. For ex.- you get into a conflict over what was observable & reportable in an attic that, in your opinon, was not safe to walk on the joists through a sea of insulation( ex. 2x3 joists) so you couldn't get out to the edge where there was black stuff on the underside of the sheathing. If your present contract does not include a limit as to how far you can reasonably be expected to see things, then maybe you should state a limit. Would it have been acceptable to visualize the area using binoculars and a flashlight or similar adjuncts or not? Yes, it is a PIA but you must learn from conflicts to better protect yourself.

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Keep the fire in the fireplace.