Not asking for advice as such but just need to vent....
Dad is mid-70s, still working (he owns his own business so no one can force him to retire!), diagnosed with mild cognitive impairment with a strong suspicion of early dementia.
He has locked himself out of the business premises before, he has just done it again with some kind of cobbled together electrical cabling on the go and the subtenant has just let themselves in to find the cabling smouldering away - there could have been a fire and god knows what.
Dad has a psychiatrist's appointment tomorrow so Mum's going to take the accident report and show, maybe the psychiatrist can talk some sense into him.
We have been at our wits' end since August, I had hoped things were getting a bit better due to the offer of a customer to buy out his knowledge (and the current subtenant is lined up to buy the building in a year's time).
But none of this will help if he sets the building on fire before he can sell/retire!
Mmmm this is tricky. You seem to have a handle on the situation and doing everything that is sensible. It is probably the risk element that has really got under your skin here - the what if? Short of electronic surveillance and a straightforward fire alarm it seems that you can only talk to others involved, do a risk assessment and agree on how you will handle it and who will do what. That at least has the advantage of joint responsibility and having tried to do what was best should the worst happen (which it probably won't). All the best!