Former hedge fund manager and Berkshire Hathaway (BRK.A - Get Report) (BRK.B - Get Report) expert Whitney Tilson says not so fast on Warren Buffett retiring. 

Tilson tells TheStreet Buffett may stay at the helm of Berkshire for at least five more years. Buffett would be 92 by then.

Watch what Tilson thinks about struggling electric car maker Tesla (TSLA - Get Report)  here.