I'm not that clued up on employment law (happy to be corrected) but would Keogh being injured long-term, where as Bennett and Lawrence being ok potentially skew things in terms of a breach of contract. Then consider neither were sentenced to actual prison time, I imagine if both were given jail time Derby may have terminated all three's contracts. I also can't be 100% sure but I think all 3 got offered new deals at reduced wages after the crash and Keogh was the only one to turn it down.
My best friend's a doctor, and he described the symptoms he experienced after the jag as follows: "lethargy, reduced appetite, fever and night sweats. Those are recognised side-effects but they weren't pleasant." On the upside, they only lasted for around 48 hours, and he's very passionate about the benefits of people - even those who aren't clinically vulnerable - getting jabbed.