My work friend's jury service has been cancelled. He's planning to not tell work and have 2 weeks off. Is he likely to get found out?

My friend at work got called a few days ago to say his jury service got cancelled. He's just not telling work.

I'm not going to tell our work but I'm worried he might get found out and lose his job. I told him to tell them, it's not worth the risk. He has 4 kids.

When he got his date confirmed, he showed the letter to our line manager. And he was put on the roster as jury service. Is there anything else the company would want to see to prove he's actually been? Do you get something at the end to say you've attended?

Update: Thanks to everyone for their comments. It seems like he's extremely likely to get found out. I'm working with him today, and he's supposed to start next Monday, so I'll try and talk some sense into him.

I can't do anymore than that and I will not be telling my line manager. My conscience will be clear if he gets found out.