95 E300D complete oil loss after change

[clickclak]

I have a 95E300 with 254K. Normally I change the oil every 3K but due to schedule missed it and went to 4k. Did an an oil and filter change last night with Delvac 15w/40, just under 2 gallons.After tightening the pan bolt and starting it to check for leaks, I found no leaks and parked the car for the night. Checked the oil this morning and had a full dipstick. The lifters on this car are beginning to make the ticking noise associated with going bad, and so I picked up a pint can of Lubro Moly MOS2, molydenum disulphide, and put in just under a quarter of the can this morning before going to work, letting it settle for 45 minutes before starting it.

After leaving, a family member called and said my car had left a small pool of oil and a trail of oil on the ground as I drove away. Luckily I was a mile from home, but no low oil light had yet come on. After I turned around, about a half mile from home the light came on. I made it back and shut the engine down, dropped the front engine insulation cover and found oil covering everything from the back of the pan by the transmission going back. It looks like the rear main seal is blown out. No oil coming from the pan bolt or topside that I can see yet, still in the process of trying to determine where the leaks are coming from and how much damage I caused to my engine. Drained some oil out so thankfully it wasn't bone dry, although the dipstick registered empty.

My initial hunch is that the additive weakened an old seal or seals and caused the leak. Any thoughts and suggestions appreciated.