Other mistake: When Sherlock was slapped, he later says he was surprised because the girl who slapped him was a "lefty." Then he rubs his right cheek and says it's leathery from all the slaps he's gotten, while the left is soft. This is backwards - anyone hitting him with their right hand would hit his left cheek.
Other mistake: The crash at the start is staged - the semi truck is driving at 20/30mph, is T-boned by the van, and stops instantly. No screech of brakes, no allowance for the driver's reaction time. In the shot of the impact it's moving at barely walking pace, hence being able to stop so quickly.
Other mistake: Near the end of the episode Dr. Watson states, "Look at the time, happy 'real' anniversary." - referring to Sherlock's one year anniversary of sobriety. The scene then cuts to a flip clock. However, the clock is set to 12:07 PM - not AM as it would be if a new day had begun. (00:41:20)