Nothing is ever that precise with building work that you can always say you are 100% right. As an example, if footings are locally required to be 1m deep, inspector could say its not good enough if in places depth only goes to 90cm or 95cm regardless of whether its clay or sand underneath. Or he could insist that you dig up entire old concrete floor to find out if its the same uniform depth of 100mm along the whole length of the floor only to say it was actually good enough when dug up and in skip. As building inspector, you seem to be able to change any remedial work to rebuilding a whole house to a modern standard. If he wants to be difficult, he can be and his department and his boss will always back him up - why wouldn't they - if I worked there I would back my colleague every time. Noseall said it - building notice says it all.