This scene in Spider-man: Homecoming where Toomes denies that he knows Spider-man’s identity is so underrated. We saw a different side of Vulture in this scene. He is ambitious on his goals as a weapons dealer. But he values his family even more. And when Peter saved Liz in DC, Toomes knew that Peter was a great kid. And at the end of their fight, Peter even tried to save him. So when he was offered a deal to kill Spider-man and reveal his identity, he denied it. Because he knew that Peter was worth saving.