I said it elsewhere and I'll say it here:

It was probably to see a mistress.

1. He wasn't really up-front about where he was going, and didn't communicate well with his staff about it.
2. Told his staff he might be going "hiking."
3. Packed hiking shit in his SUV, you know, so his wife would buy the story, but didn't take the hinking stuff.
4. Wife didn't even know where he was going.
5. Wouldn't answer phone.

Ladies: I ask you: If YOUR husband did something like this, what's the FIRST thing that would enter your mind?