I can understand why your friend and his other colleagues aren’t exactly keen to see a nasty employer again, but I agree with you that we shouldn’t wish ill on others when they’re ill. Perhaps it’s also a good opportunity for your friend to pay the sick boss a visit and take something along. Who knows, he might then find out more about how things are going or about this person’s character. Who knows, if there’s a bit of human contact, he might change once he’s better, or he might simply decide to take a job that’s less stressful. Let’s be honest: it’s not always great to be the one calling the shots, especially if no one likes it or my mum said otherwise, because there’s a difference between who’s in charge and who has to carry out the orders.
You are right, those are really good pointers and good advice.
Nothing is easy in life, we all have try our best to do the right thing. Being inhumane is not good for anyone, we all need to stick together. I guess that's all that matters.