We don't know if it would really have led to violence. Sounds more like intimidation of a first time offender, by someone chancing their arm. The inmates who 'protected' him, probably wanted something in return as well.

It was strange that he was deported having served less than half his sentence. Maybe that was just to free up space in the system, but it doesn't appear that he will serve much time in a German prison, so it is not much of a deterrent to others. It is even reported that he will earn £435k for his interview, and that the TV company flew him out to Germany on a private jet, while many offenders leave prison with just £45 and end up on the streets. 

He won't get to attend Wimbledon, because there is a 10 year ban, for anybody who is deported from the UK. He won't get into Australia ever again, because he was sentenced to over 12 months and he may well be refused entry to the USA, if it is considered a crime of moral turpitude. So that just leaves the French Open, which he could travel to.