Start at 2:50 or so:
Centro is boxed in, BB is slightly behind him, moving up. Centro decides to go wide as BB is doing this. Centro tags BB's hip, as if to say "Don't cut me off, bro." BB gestures like "You have space to go...see? (it is opening up because Leo is moving up as well)" in case Centro wants to go for it, and indicating he won't challenge if Centro wants to go for it (BB would likely prefer to draft Centro at this stage anyway in preference to taking the lead himself). Centro declines the opportunity and BB accelerates into the lead.
So it is BB acting in his self-interest (to not tangle up with Centro), which doesn't conflict with Centro. Neither wanted the move that bad, but BB ends up taking it by default.
Didn't affect the race outcome, except that BB had to accelerate a little sharper having gone so wide, to get the lead before the curve.