What happened?Tesla shares fell 3.7% on Tuesday (NASDAQ:TSLA), according to a report. The decline was at 12:25 p.m.The stock of the electric-car manufacturer was down for two reasons. One, a bearish day in the stock market and two, comments by Tesla CEO Elon Musk over weekend about how it has been more difficult to roll out self-driving-like features in its vehicle fleet.What are you waiting for?Musk was teasing a Tesla owner on Twitter about missing the deadline to roll out its next beta version. This technology requires drivers to be attentive behind the wheel and ready for the take-over. The CEO also admitted that he didn't expect to achieve "generalized self driving" but it is difficult in retrospect. Musk, however, did say that the next beta version "is shipping soon,"Meanwhile, a 0.8% drop in the S&P 500 at this time reflects a bearish day on the overall market which likely weighed down on the growth stock.What now?Musk deserves credit for recognizing that any driver technology in production vehicles that could even remotely resemble full self-driving capability would be quite impressive. This isn't your typical technological advancement.However, Tesla could be criticized for repeatedly failing to update its self-driving technology.