Here's why he left:
* Personal Choice: Weatherly chose to leave the show to pursue other opportunities, including starring in the CBS series "Bull". He had been on NCIS for 13 years and wanted to explore new roles and projects.
* Contractual End: His contract with NCIS was coming to an end, and he decided not to renew it.
* Creative Direction: There were also reports of some creative differences between Weatherly and the showrunners, although nothing specific was confirmed.
DiNozzo's Exit:
DiNozzo's exit was emotional and impactful. He left to take care of his daughter, who he discovered was his late girlfriend's child. He was also searching for closure after years of dealing with his father's death and other personal trauma.
While he left the show, he did return for a brief appearance in Season 16, Episode 10, which aired in January 2019.
It's important to note that "Muse" is not a character on NCIS. You may be mistaking the name of the actor with a fictional character from a different TV show.