I would say yes. Its hard to know for sure as we can't see all the things that were done nor are we there to look at what is actually happening. But that said, its oil rleated, its got to do with the pressure in the crank case / valve cover and the item that controls that is the Oil seperator / crank case relief valve, which is what they replaced.

If it was me, I would go back and ask them to please fix it right. Shouldn't happen again that quickly.