I saw oil in the same place on mine (bw sump & trans) with a fresh oil pan gasket & really the only way it's going to leak back there is at the seal from what I recall.

Yes, removing the oil pan and replacing the front seal is a Bi***. You couldn't pay me to do that again, short of having the truck up on a 4-post lift but never again will I lay on my back & drop the oil pan; you have to be bound & determined to complete that exercise but I was already 2-weeks in on a head gasket replace, I knew the front seal was shot, plus a lot of crud fell into the open valley which I flushed with oil so had to clean the sump out & ya, that was some work. I think I removed the pan starting at 9:00 pm and had the new crank seal in, pan gasket on & bolts tourqued to spec by noon the next day with a 1-hour break. For some reason it took 3 attempts to get the sump seated correctly so that set me back 2-hrs.

 

That's sounds scary!

May be i will go around and tighten oil pan bolts, get rid of synth oil add some sort of oil sealers to band Aid for the time being. see if that helps.