Even bearings doesn't necessarily indicate that Rohloff knows what caused the problem. Seals they would replace routinely.
I once gave a broken Apple computer to the guy with the factory right next to Apple on Hollyhill, where they did all Apple's production line rectification, and when I picked it up I asked him, "What was wrong with it?"
"Dunno."
"Then how did you fix it?"
"We just reflowed the entire board, then switched it on. It worked."
"Duh."
"Quite."
Unless the problem is really serious and likely to reoccur often, I doubt it is worth Rohloff's time to track it down if a cheap fix like bearings and seals fixes it. Quick turnaround as a sales and publicity tool is probably more valuable to them than knowing exactly what caused a rare problem.
Andre Jute