Well, I'm pretty sure I would remember if my business associate just up and disappeared without so much as a phone call.
Actually, CM did remember quite a bit about that last day.
That evening call? At first, he didn't want to speak with Joseph. Then he was in the loo, and missed the call. And then there are those pesky phone records that showed no call at all was received by CM that night. And - by his own words he was definitely the last person JM saw that day. Plus, according to CM, Joey was also at his desk at home around 5:30 on 2/4.
With the burials in his back yard, so to speak, CM remembered quite a lot that perhaps he shouldn't have shared with LE.