Keith Norman, their general secretary says: "The plot is almost equally depressing. The driver, it seems, is told about the 'three and out' rule. According to the publicity blurb, 'If you have three fatal accidents within a month, you're out of a job ... but with a huge pay off.' So the 'hero' sets out to find another suicide victim. If he finds one he will be given 'enough cash to pay off his debts and retire to a Scottish idyll'. Have you ever heard such nonsense? Clearly whoever wrote it knows nothing about train drivers and even less about their conditions. I'm mystified why writers choose subjects about which they're entirely ignorant."
I've not seen the film, so can't really comment at the moment on whether Keith Norman's had a sense of humour failure. It may come across as a massive, massive spoof that clearly isn't supposed to be taken remotely seriously. It may make them look like, & to quote Keith Norman, "callous self seeking half wits".
Who knows? Let's just hope they don't go on strike about it.