Unless it was leaking externally the problem isn't the adapter. If anything the oil would be bypassing the filter. Your drop in pressure seems either coincidental to the engine warming up or a symptom of the bearing failure, depending on the failure.
I think the pressure drop is a symptom not a cause of the problem.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
