That's a good question and I think it's a very personal answer. For me I started DB to save my M. I didn't succeed in that but I did succeed in saving myself. As with IS that's where he needs to be. I don't believe he's there right now.
When an A is exposed. The WW will squirm any which way to make out its all in your head. Or in my case it wasn't an A because they only kissed. Ha, now look at the mess she's in. And that's kinda my point on the Intel. If there is an A, and it sure looks that way then she can't be given a chance to turn it all around and make it look like IS is just being paranoid. Because she'll try that.
Me:43 Her:42 M:14 S:9 EA started 2014/03 (or there abouts) PA started 2014/05/30 BD:2014/11/05 I left 2015/10/01 I returned 2015/05/02 She left 2015/06/10 OM still on the go.