I'm sure it isn't funny, but I find it hard to believe that picking up the phone a couple of dozen times per day can cause RSI. It's not exactly a restrictive action on the muscles, is it?
rsi = repetitive strain injury. Yes, repeated actions can do it, even quite simple, everyday ones that leave other people unaffected. Doubtless he should have been sitting more ergonomically; but I've had it, I didn't like it, and I sympathise with any fellow sufferer however rich.