Dealer didn't change my oil filter? VQ40

OK- so I just did my 2nd oil change at 6500 miles. The first one, at 3000 miles- I took advantage of a free one by the dealer where I bought my truck, and provided the Mobil 1 5w-30 myself.

2 suspicious things:
1- I provided the dealer w/ a 5 quart bottle and a ~2 quart left bottle, the 2 quarts I found to be untouched afterwards. (Granted, even with a filter today I found 5 quarts was fine- 1/2 way up dip stick, didnt need much topping).
2- The filter I had to take off today for my 2nd change was a real bi*ch and had the japanese writing on it and pn 15208-31U0D , which I've read is a factory filter only. From a different dealer I was provided with a 15208-31U00 that I used today. It was identical to the 31U0D.

So- did the dealer change my filter the first time? I'm calling tomorrow to see if they stock the 31U0D filter. If not I'm calling B.S. on them.
Thoughts? :thatswck: