What are peoples opinions on this? Some have advised this blue orb looking ghost bubble underneath the crystal on my PO 8500 could be a manufacturing defect. Some have also said this could be a small amount of moisture? Has anyone see this before, if so, what can omega do about it?

 

I've not seen something like that before. At first I would have said it was one of those Omega symbol markings that they put on every crystal but your issue looks different.

If the timepiece is under warranty take it to the Boutique and they'll handle it. If it's not then still do so as they could at least diagnose the problem.