Goofs

The Captain gave Watson a police escort to her parents house, but Mallik claims she has no alibi because her father was away and her mother is not a reliable witness, so there's no evidence she actually went to the house, and nobody seems to remember the police officers who could confirm her story.

According to Rowan, the impetus behind his attempt to murder Watson was finding out that Bazemore had committed suicide because Watson had revealed that Rowan murdered his husband. But according to the recording Mallik has, Rowan called Bazemore the following morning to make excuses for the accusations made against him.

Joan Watson lacks the size and strength to have dumped the body of a man twice her size. Especially after being viciously beaten by said man, leaving her with multiple contusions and fractured ribs. Doctors are so quick to offer strong pain medication for fractured ribs because just breathing can be agony, moving is worse, and lugging a body around is out of the question.

It appears the writers intended to have Rowan murdered after making a call to set Watson up, then changed their minds but not the script. The recording of the murder was both nonsensical, and too convenient. Having tried, and failed, to murdered Watson because he blamed her for Bazemore's death, Rowan called the dead man to leave a message at the exact right right moment to capture his unusually loud beating, and him implicating Watson, but not saying another word. He didn't even say "stop", just an unsurprised "Joan".