"Too well lubricated?"!

Lack of lubricarion leads to:
-wear on the ball and socket, increasing clearances.
-difficulty getting the lock to properly latch.

As to the original statement (quoted), maybe the ball or socket were worn beyond limits, lubing removed some "crud" that was holding things together. This then allowed a "properly pinned/locked joint to come apart".
Go back to root cause, in my "non degreed mechanical engineering opinion".

IMHO, many things need to be cleaned, looked at, lubed a few times a year, at a good annual inspection at a minimum. Reducing wear and easing use of controls/systems are a benefit.