Yes, the oil leak could be the pin. It depends on where it hangs up at if it falls all the way out of the hole. My brother has a 95 that developed a leak up front and he took it to a dealer. They couldn't find the leak. Told him about the dowel pin and how to get to the area behind the fan. He pulled the fan and pully off and the housing was cracked behind the pully where it could not be seen. He was lucky as when he pulled the cover, the pin was laying on a shelf behind one of the gears. He had to replace the cover as well as the "standoff" that holds the cover away from the gears.
Make sure the front crank seal is not the source of the oil. The front cover will need to come off in either case. Some guys have replace the seal with the cover on but I had trouble getting the thing in even with the cover laying on the ground in front of me!
Good luck on finding the problem.