Other than the Jackson long TD in the third quarter, the defense played much better than the first half. So it appear they did clean up a lot of their issues after halftime.
On special teams, they made sure Sanders kickoffs were deeper with no returns.
As far as Tua throwing into tight cover is concerned. The fact is defensive backs in the NFL are good and it’s their job to cover the receivers. Therefore QB’s are frequently throwing into tight coverage and sometimes the defensive back intercepts the ball but most of the time the receiver makes the catch.
If Tua wasn’t willing to throw into tight coverage on occasion, the Dolphins might not have won the game today. Because Waddle was completely covered on that last TD pass but Tua threw it anyway and Waddle came down with the catch.