If it had been a train driver who had expertly delt with an emergancy and found himself being breath tested for it on the word of a passenger I doubt that any trains would be running in the UK today. Its a crazy situation.
Unfortunately the day has already arrived.
About two years ago someone walked across the track at Hitchin station into the path of a High Speed Train (running at 125 mph). Plod arrived, and insisted on breathalysing the train driver (presumably for being responsible and not stopping or steering out of the way). Turned out that said Driver's test was positive. Now for the GOOD bit. They arrest him and take him away, grinning happily, and thinking of promotion. When they get to the Police Station it seems that their breath test machine was not working correctly. Driver was definitely NOT drunk and had absolutely NO alcohol at all.
I should SO love to have been him. I suspect the payout could be rather large!
Scenario No. 2. Terminal station in Surrey. Train arriving into station encounters wet greasy rails with result that it gently touches the buffer stops. Plod who apparantly is on site sees this and immediately arrests and removes Driver form the scene. This without ANY information being passed to anyone and resulting in the train being left un-secured. Such action is in the view of all right thinking railwaymen criminal. Unfortunately the stupid arrogant arseholes who arrested him have presumably got off with it. By the way that Driver was NOT under the influence either.
From a railwayman's point of view the one good thing is that we still have our own Police force, whose Officers are still embodied with common sense. They understand the railways and how we operate.
On the occasions when they do ask us to provide a specimen we understand that they need us to do so, and are not on some power trip. There is still thus a very considerable respect for OUR Police against the civil police who on occasions can be total wankers when dealing with things off the road.