Based on a true story...

I'm no barrister, but what I got from it is that the legal eagles used the threat of Joint Enterprise Murder against the four young men who had not struck a deal (as the pizza shop worker did).

It was the threat of all of them being tried under JEM and all facing life in prison that caused them all to be willing to cop a plea and grass their mate who actually did the stabbing.

Although the young men in turn used threats in order to get their mate who did the stabbing to confess and own up, so the rest of them could plea down to a lesser charge while he went to prison for the murder. We saw them telling their stabber mate they'd do for him in prison once they all got there, if he did not confess.

There was no trial. It all was done under a plea bargain. With the culprit confessing.

So no, technically they were not tried under Joint Enterprise Murder.

But that was rather the interesting way McGovern treated the law, IMHO. He didn't even show a JEM conviction for the innocent guys with life sentences.

He took another tack, which was to show how even the existence of JEM can get 3 guys into prison sentences, especially Johnjo who knew nothing and did nothing and just gave his mates a ride. The crown prosecutor used a threat of trial under JEM to force a result then and there. The court saved the cost of four trials, plus the chance that some good barrister would get guys like Johnjo off on a technicality, etc.

So in the end, it made JEM look even worse as a law than simply trying a group of associated guys under it for murder.

McGovern was saying you don't have to go to prison for life for a group of associated men or women in order to be affected by JEM.

You can still go to prison, even without a trial!