Clark Gillies rips John Tavares' handling of departure from Islanders'I think he made a huge mistake and it cost this franchise'4/9/2019, 1:02 PMFeb 28, 2019; Brooklyn, NY, USA; Toronto Maple Leafs center John Tavares (91) skates past a sign held by a fan of the New York Islanders during warm ups before a game at the Nassau Veterans Memorial Coliseum. Mandatory Credit: Brad Penner-USA TODAY Sports / Brad Penner