Generally, no. Wrongful dismissal, human rights, employment related litigation isn't usually insurable.
Particularly today.
It has become all too easy, and all too common, for those who can get away with it to claim 'discrimination' when terminated to elicit a higher payout. It often works, because it is the hardest to disprove and among the worst for corporate reputation.
Just because it has settled doesn't mean there was money paid, or a substantial amount paid. Very often, as the claim winds through discoveries and hearings, reality and/or truth come into better focus.
Virtually all employment related litigation is on a contingency fee basis. If the litigating law firm has determined that the defendant is unlikely to be able to satisfy a judgement, they will work to settle as quickly as possible, on whatever terms are possible - including walking away to avoid incurring any more costs.