Roger, for God’s sake give your head a shake! Of coarse he is trying to pull one over on you. Don’t allow that mechanic to take advantage of your (Relative) inexperience with engines. And, if any one who has submitted a reply to your post tells you that the mechanic needs to fix one thing at a time they are probably dishonest mechanics themselves: "Birds of a feather…"
Two things you need to check for yourself before towing the car to another shop, which you really should just break down and do and make this be one of those times where he hasn’t fooled you twice. Get on the ground and look at the oil pan in the front area of the engine (Where towing aparatuses [aparati?] may have contacted the engine.). You’ll probably find a hole in the oil pan where the tow truck driver did a poor job hooking up your car. I drove tow trucks for ten years while going through school. If they used a “wheel lift” type truck they may have let the front wheels sit too low into the towing frame, thus allowing the towing assembly to contact the lowest part of your engine whenever he went over a bump. Even if there was a different type of towing system used (Flatbed, sling, etc) my opinion is still the same.
Secondly, it just very well could be that a previous car left oil on the ground and the mechanic didn’t bother to find the source or verify the leak. It could be that he is distracting you with the computer thing to make himself look honest. I don’t think he is honest in the least - heck, he may not even be sober. Never, ever take your car to a dealership mechanic. Take the time to find yourself a good, honest independant shop. And not Midas, Jiffy lube, or any other convenience shop. Their mechanics are worse then the dealership mechanics.
Over the past few years I have dealt with some dealerships while restoring old Muscle cars - had no choice type of thing. Putting it mildly, dealership parts departments and repair shops are filled with slimy degenerates.
TRUST ME.