A solitary incident does not qualify as a "lemon." It's a serious failure, for sure, but hopefully, as the OP has stated, it will be resolved quickly.
The OP's frustration is toward the failed service, which has nothing to do with the vehicle being a "lemon."
As the previous owner of more than 2 dozen vehicles, new and used, with several serious early failures of VAG cars, my experience predicts that after this initial failure, the car will be just fine.
No one can predict what improvements, if any, will occur with Tesla service. My feeling is that it's much like any other auto manufacturer: the service center is limited by the quality of local mgmt, and staffing quality.