I'd like to put the whole thing into context. When asked his opinion on the strikes he initially said it was "fantastic" as it made getting around so much easier.
"Everybody's stayed at home, you could wiz about, restaurants are empty..airports, people streaming through."
Then to follow this up he indicated that as this is the BBC he needed to be balanced and give the counter view (mocking the BBC's editorial guidelines here was probably his aim) and that is when he said:
"I'd have them all shot. I'd take them outside and execute them in front of their families."
The clip can be seen here:
Now I don't think anyone can say that these were sensible comments, personally I didn't find them particularly funny, but at the end of the day this was a joke that you can tell he was saying for effect. In my mind there is a clear pause where he is sensing how the first part of the joke ("I'd have them all shot") went down with the studio audience (there was some laughter) before he decided it was good enough to expand on.
You can't go around summarily sacking people for doing exactly what you pay them to do just because one of their attempts to fulfil their job description isn't well received - even if it warranted it there is due process to be followed, something that Unions have spent years campaigning for.
David Allen Green has written an excellent post on his blog analysing the press release by Unison. The key question he raises for me is that is it a good use of Unison's finite resources to be trying to get someone sacked - is this really in the best interests of their members?
The other excellent post I've read on this issue was by Dave Gorman - "Jeremy Clarkson should be lined up and shot*" (Not really). He is highlighting the hypocrisy of people, who would possibly have been defending the twitter joke trial where Paul Chambers was arrested for the following tweet:
"Crap! Robin Hood airport is closed. You've got a week and a bit to get your shit together otherwise I'm blowing the airport sky high!!"
Getting the police involved (as has been suggested as a possibility by Unison) would be as ridiculous as the twitter joke case. I don't think it should be a universal right to not be offended. If it were then we'd still be living in a Puritan society as almost everything is going to cause offence to someone. He was not encouraging people to go out and shoot any striker he was just trying to make a controversial joke, and oh look it worked - As David Allen Green said, he's turned the whole story (and Unison have facilitated it) to be about him rather than the aims of those who went on strike. It would have served them better to treat him as an irrelevance and perhaps made a complaint to the PCC.
At the end of the day, Clarkson has the right to say what he likes, that's the great thing about freedom of speech. I for one would hate to see that right watered down further.