I can pretty much guarantee that the trans fluid level wasn't checked.

I guess the only real problem in DIY on the trans oil change would be making sure the level is correct. This trans is super-critical on the level. There is a special tool dipstick required (there is no dipstick in the tube, the tube simply has a cap on top, no stick underneath the cap), and also the trans fluid temp is monitored while checking the level (the stick is graduated according to temp, but MB insists that the level is checked at 80C).
The fluid temp sensor is built into the trans, and the reading is done using the MB shop computer. I would trust the indy IF you know they have a scanner capable of monitoring this temp sensor, I'm sure some do, but lots won't. I wouldn't recommend DIY on it, just not worth the risk. SOME here I believe say they have done it, still not my recommendation.

On the diff oil, knock yourself out.......

Gilly