I think it's
because of the 1.7.2 Sprint Key that you rubberband.
The rubberbanding is caused by NoCheat+ (NCP, in other words the anti-hack plugin, whichever MCSG has.)
The anti-cheat is made to stop cheats/hacks, and one of the most common hacks is Sprint Hacks, such as BSM.
The anti-cheat is configured to stop BSMers, sprint hackers, etc. (I'm going to ignore other aspects of the NCP for this thread)
When someone sprint hacks (Including BSM) The system tries to stop them, literally - It
stops them. With the rubber banding.
The new Sprint key makes sprint very similar to BSM and other basic sprint hacks, and thus the system cannot easily distinguish between the two. Because sometimes you pull of a turn or start sprint in a funny manner, the system thinks you're using a mod/hack, and stops you.
I'm assuming you're using the sprint key in 1.7.2, since during the livestream you absolutely loved it