Button switching to Red Bull

Button can't stop himself from showing his liking for Red Bull when he entered the pit crew of Red Bull for regular change of tyre in Chinese GP 2011. What would happen to Sebastian Vettel coming behind him if Button would had taken a lot of time in pits. Would Mclaren be so generous to provide an option for Sebastian to change his tyres in Mclaren pit crew.

Its just like that "The big rivals approaches to enemy territory for help."