I'm fortified in my previous conclusion this is a disastrous documentary for SWR
Oh not at all, it's exactly what they want. I think you misunderstand the psychology.
The people pushing through barriers, running away, being abusive and causing ASB will do that anyway. They will not be watching this, and it wouldn't change their behaviour anyway.
Those don't run away, readily admit to ticketing offences when asked and hand over their details aren't going to suddenly start pushing through barriers. They're the ones that are terrified in the moment!
SWR presumably hope that by demonstrating their 'thorough' approach, they'll scare a few from the latter category (directly or transitively) into paying the right fare, saving them the investigation and converting a few people they'd never catch into fare paying customers
Case in point.
The former are probably a bit of a lost cause, so they'll make their lives annoying and difficult, getting the BTP where they can.
Nothing in that documentary is new to anyone with half a brain cell and/or Google.