He braved his fear of heights to get the team through Cuba.
In order to retrieve information necessary to convict a Serbian war criminal, Happy and Toby needed to break into his security deposit box. Naturally, it was in the most secure bank in Cuba. In an effort to break in through the ceiling, the team needed Sylvester to climb a phone pole where he could disable the bank's alarm. Toby distracted the human calculator from his fear of hights by asking him uncomfortable questions about his feelings for Meg. It may have boiled Sylvester's blood, but also distracted him enough that he climbed all the way to the top of the pole before he even realized it.