I would change the communication grade to F-, personally. This was a dangerous issue with potentially horrific consequences to both the driver and the company, and Tesla failed to alert those who might have been affected. But, a conditional A+ for the quick fix, assuming that it did resolve the issue without breaking anything else. I really, really hope Tesla, despite the lack of a media firestorm or a tragic accident, takes this incident to heart and THOROUGHLY tests all OTA updates before pushing them out. This isn't a game console or a phone, this is a tank like missile that could do serious damage if they eff something up. People don't need firmware updates ASAP, but they do absolutely need to know that the car will perform as it is supposed to all the time.