Last tuesday I took my car into the dealership for the 36,000 mile service, which is a minor service if I'm not mistaken. So I pick up the car and head home when not but 10 minutes later, smoke starts to enter the cabin!

I pull over, opened the hood, and noticed oil had spilled out from underneath the oil cap. At first I thought the tech was careless and spilled oil on the engine block, so I went right back to the dealership where they cleaned up the mess and gave me a new oil cap. They claim that the cap's tabs tend to warp and allow oil to seep out. With a new cap in place, the spill cleaned, and an apology from the dealership I went home.
Now yesterday I noticed the oil temp gauge needle nearly at the 210 mark after driving only 30 minutes. This is the first time I've seen it so high. Normally the needle is just past the first dot, even after some of my more spirited driving excursions.
I let the car cool down, for an hour, and checked the oil level. Sure enough, the tech had over filled the engine.

According to the dipstick (after 3 measurements) the oil level was past the full level.
So my questions are: a. I assume the high oil level is the reason for the elevated oil temp and b. can this be damaging to the car?
ALX
PS. I'm going to take issue with the dealership....