Anybody seen my keys?

Yesterday B. and I popped into Harleston to do a bit of shopping. The last job was to get a new battery for my stopwatch. We'd taken the camper and we both have a key to the camper on our keyring, and B. happened to be using my keys. We managed to park opposite the shop, popped inside, and as I was looking at the other stopwatches, B. quickly nipped to the cashpoint next door. I paid for my stopwatch, we put our stuff away, he says 'can I have the keys please?'. No sign of them. I knew he hadn't given them to me, but they weren't in his pocket and not in my bag either. We'd not done any browsing in the shop and they weren't on the floor anywhere. Panic ensued: my keyring has my (only!) house key and my car keys on it. It quickly dawned on me that the most likely scenario was that someone had picked them up accidentally, but it's a Bank Holiday over here this weekend and if someone did find them before the shops shut yesterday, what were the chances of them remembering which shop they'd picked them up from? We left our contact number with the shop, went to the police station to leave our number there as well and then went home - feeling very unable to do anything but wait. Fortunately I'd remembered who else was in the shop at the same time, and more fortunately the lady helping there had the sense to remember that that lady had ordered something and left her telephone number. So they rang her and left a message, and lo and behold, at 2.30 that afternoon, the shop rang to say that the keys had turned up. The man in the shop at the same time as me had the same make car as me, had seen the keys and assumed they were his, and put them in his pocket. When they heard the message on the answer phone, he checked his pockets and found my keys there.
Funnily enough, instead of feeling just relieved, I just felt incredibly angry. We both had lots to do yesterday and most of our day was completely mucked up by driving around and trying to think up solutions, just because someone was so stupid as to pick up the wrong set of keys. When B. picked the keys up again and it didn't seem the bloke had even apologised, I got even angrier. Someone said to me 'good to see there are still honest folk out there' - well he shouldn't have taken them in the first place!!
By 8 pm last night we were both shattered. We'd achieved nothing all day and we were in bed by 10.30 pm, not unusual for me but B. doesn't normally make it to bed before midnight, and that constitutes an early night for him.
Feeling a bit better this morning, but needless to say, I'm not leaving my keys out of my sight!