Islandgirl, I'm going with juvenile raccoon. Final answer. Whatever it was had a hard time getting through that 1"x2" space and I think a weasel would have just slipped through. We're upgrading the wire today. Although I'd like to think I scared it away for good by chasing it, naked, at 2am... I'm guessing it'll be back.
I'm sure it will be back. You're plan to upgrade fencing is great and should help keep future intruders at bay. You could always set a live trap baited with a can of tuna, catfood, chicken (although I think I'd avoid the chicken) etc. If you want to catch it and then contact local fish and game and have them remove it/relocate it.
