It is and was all about Tannehill's accuracy. Of the 10 completions in the first half he was bailed out on almost 5 passes by his intended receivers.
Though his second half numbers were less than the first half numbers he had more quality throws even the throwaways where he didn't force the ball into bad coverage. It does not come to a surprise that we scored 23 unanswered points in the second half because Tannehill actually played like a QB, a smart QB.
Numbers are just numbers.
Receivers failed Tannehill in the 2nd half. Off the top of my head, Wallace, Clay, and Simms all had big drops. Tannehill failed the team in the 1st. Anyone watching the game could see as much.