Do you honestly think he received oral sex from his wife, returned at 2pm then received a call to a client meeting and thought to himself "oh they timed that well, I can kill Ann on my way there/back"?We don't know if he was wearing clothes when he hypothetically committed the murder.
Also, unless there is photographic evidence he was wearing the same clothes I'm not sure anyone can prove that he was.
IMO
And he managed not to leave a trace of blood...
And dispose of the weapon...
Dispose of the duplicate clothing...
And waste his life/time on the case...
And waste his time visiting Ann's grave during his next relationship...
And risk discussing the case in a documentary...
Attach a probability to each event, multiple them together and what do you get? A very small number?