Several thoughts come to mind...
1) He may be losing more of his "functional" brain if he can't cover his tracks. This does not bode well for work.
2) He may not be alone - and if he is conducting an affair with a co-worker he is really asking for trouble especially if his affair partner is a subordinate.
3) The US Embassy in the UK has a list of attorneys/solicitors on their website, including those who specialize in family law. The list is not an endorsement, but it's a start.