Leaking Upper Oil Pan Seal

[Jay in Phoenix]

I have a 2013 RX350.  The timing belt cover developed a leak at 64k miles 2 years ago this past July (July 2017).  I fortunately purchased an extended warranty when I purchased the car new, so the repair was covered.

This past June I saw oil on my garage floor so took it to my local mechanic for an opinion.  He told me the leak was coming from what appeared to be a past repair to the timing belt covered.  I called my local Lexus Dealer where the original repair was done to be told that repairs are warranty for 1 year and I was almost at 2 years......sorry not covered.  I asked about my extended warranty to discover it expired the past November.....sorry not covered.

After speaking with a great Lexus Financial Advisor, at that dealership, he help me get someone to agree to at least see if the leak was from the same area.  I took the car in (July of the year), it was checked out and I was told one of the timing cover bolts was leaking and the gasket/seal for that bolt was replaced and the bolt properly torqued.  I was advised to return after about 1000 miles.

I returned today (leak was still active but not as bad) and was told the leak was from an entirely different area.......the “upper oil pan gasket”.  Not covered.

The mechanic nor the service writer could explain why that area (which is surprisingly close to the original problem) suddenly developed a leak. I asked several questions including if the leak could be related to the past repair.....”no, not possible” was the response.  

Can anyone help me understand how this problem could happen with this kind of a vehicle with just over 84k miles. 

Thanks In Advance.