As someone else hinted, there may be nothing to "fix", but rather this seems like a specific situation that it had just never encountered before. Adjusting the model to cause a safe response to that particular single rare situation (either manually or by accidental training) does not solve the apparent problem that the machine is not able to comprehend the world.
At least that is how I (as a non-expert) imagine these models work -- the model has an excellent chance of crashing at every new unique situation it encounters out of a nearly unlimited set of possible situations (which implies a high frequency of encountering new situations).
So in future your self driving car might be recalled at any random time because a new corner case from an infinity was found. If the car can't be driven by a human all owners of thsi cars will be stuck wherever they were at that moment.
This will be interesting to watch. If I bought an autonomous car and the autonomous mode was disabled for a few days or even weeks while a bug was fixed I can always fall back to driving it myself. If that's not possible (maybe because the car doesn't support it or I didn't have a licence or human drivers had been banned) and suddenly it's a whole different situation. Of course owning a car might become less common in itself, if you're just taking them like an Uber you can always switch to a different company.
At least that is how I (as a non-expert) imagine these models work -- the model has an excellent chance of crashing at every new unique situation it encounters out of a nearly unlimited set of possible situations (which implies a high frequency of encountering new situations).