Well the OP mention of Idiot, it wasn't him that was the idiot, but the LBS, if they can't put a wheel on a bike the right way round what hope have they??
And if you need more proof that they are idiots, they were running the service vehicle for the Norwich 100 today, I'd finished and was home watching the Grand Prix when a female friend who was doing the ride called, I thought it was to say she had finished but no, unfortunately with 10 miles to go her chain broke, the CyclesUK car pulled up 20 mins later and offered to fix it, 30 mins later they said sorry you need a new chain which we don't have, you need to call someone to be collected, so I was called.
Just in case I took my tool case, drove out to where she was and had a quick look, yes the chain had broke (side plate popped) anyway 5 mins later and 2 links shorter chain she was on her way, she called me later to say she'd finished

Yes chain does need to be replaced but at least a simple fix meant she could finish her ride.
So how can a
cycle store and repair guy not fix a chain, what took him 30 mins to say it needs replacing, when 5 mins was all it needed, oh and yes he had a full tool chest in the car. Needless to say she was less than happy about this, more so as it was raining and she wasn't even offered to sit in the car while he worked on the bike, they have lost a customer for life and anyone she tells about this.
So sorry but Norwich CycleUK are the pants, can't mount a wheel correctly and can't fix a chain at the roadside, Idiots!!