Of course it is, why didn't they sack him before this then? Why suddenly they sack him now for the December comment. Did they really go through every off air comment to see if he's said anything they dont like? It is pathetic.
If I committed multiple sackable offenses at work, I'd expect to be sacked when my employers found out about it.
Arguing that they shouldn't do it because it didn't come to light right away isn't much of an argument, is it.