No, it didn’t crash. I had to disassemble mini grisbot in order to perform surgery on the right servo, whose centering had drifted so much that the wheel could not turn forward.
To keep the potentiometer shaft from twisting (thereby drifting) again, I fill the potentiometer well with glue. Online instructions for servo conversion recommend hot glue for fixing the position of the pot shaft, but surface tension causes the glue to bead and that interferes with the turning of the bottom gear. By applying cold glue with a toothpick, I can spread the glue flat.
This is what I did on the other servo, and I haven’t had any problems with that one . . . yet.