Sometimes you just have to walk away.
Good owner told by a mechanic verbally that the mechanic is concerned about something — will listen and ask questions — and if they’re at all mechanically inclined they will know the difference between a cracked piece of plastic fairing and a cracked spinner plate and the forces involved and the seriousness of each.
They’ll likely ask to put the airplane in the shop and start working with the mechanic to get the dangerous stuff done first, maybe defer some stuff for later, and get their airplane back into reasonable shape over time with an agreed plan.
And probably be quietly ticked at whoever signed it off with serious problems.
Bad owner will prefer you keep it all verbal or to yourself, and might go shop around for someone ultra cheap to address a few things. Anyone who’ll conveniently ignore other things. If they bother at all.
Best advice I can give is keep it verbal unless he asked you to inspect it, and definitely keep your signature far away from his logbooks. That’s my owner side perspective anyway. You can’t really interject yourself into their mess unless they request it.
Your reputation as a straight shooter will get around via word of mouth and you’ll have the owners who want to be more like the first example than the latter one, keeping you busy enough you won’t need the bad ones.
We’re very picky about who we let work on our plane. If I don’t have a reference from another owner I know or someone else I trust, I get really nervous and protective of the airplane if I’m forced to put it into an unknown shop.
My co-owner can also be nervous when stuff happens on the road, and it’s not about the money, it’s about whoever is with the airplane when it breaks has to decide if they trust the person wrenching on it.
The good owners know what you know. The successful and safe folks in this biz help each other out and owners don’t force mechanics into making iffy decisions about airworthiness, as long as the mechanic isn’t making big fusses over non-airworthiness or safety items. Just inform and educate and most owners who care will want stuff fixed anyway. If we wanted to fly a clapped out rental, there’s plenty of those on the flight line at every airport.
Bad owners just aren’t motivated the same as a proud and happy airplane owner for whatever reasons. Avoid engaging once you see they’re not going to participate in the process, seems best to this non-mechanic. It’s a shame if the idiots’ airplanes break while they’re flying them and even worse if they hurt a passenger with their neglect, but sometimes you weren’t engaged by them to inspect, and they don’t want your assessment anyway. Sad, but have seen it for a long long time.
Scariest flight I’ve ever done was in an owner’s plane who had that same attitude as your guy. Managed to get the airplane back to the hangar in one piece after emergency gear was rolled to the runway and the outcome of the flight was definitely in doubt. He put it away and never said a word about fixing it other than “that problem keeps coming up” and he didn’t acknowledge the three other problems during the flight at all. Total denial that he couldn’t afford to maintain his slowly failing toy.
Told my two non-pilot friends who flew with him often up until that trip to never get in his airplanes ever again, and explained to them, away from him in private, why I said that, and what I saw in his ownership behavior that was abnormal from other owners I knew.
They never did fly with him again, so I felt like I got a small win out of it that day.