Hmmm....since it's engine oil and not gear oil leaking, your axle seals are likely NOT the culprit. While it is true the front axle does run through the pan, it actually runs through a conduit that is separate from the sump...the axle is not bathed inside the sump and thus would NOT drip motor oil. If you're experiencing oil dripping in the left side of the engine in the vicinity of the diff/front axles, it's likely the oil filter housing gasket that's making a mess as it's rather close, and has the potential to coat much of that side in oil if left long enough.

Im not discrediting your "specialist" but I'd look at getting another opinion.

You can see the conduit that runs the width of the pan on the attached pic...

Attached Images

 

__________________