Ted was able to hold his own in a fight with John, so why didn't he fight off his kidnappers?
Two against one? Also realize this: Ted is the sort of Jerk Ass With A Heart Of Gold who is comfortable beating the crap out of his friend. But John? The entire story is about John holding on to childhood and that means Ted. John can't win in a fight with Ted, because John would never use any thing close to full strength on his friend. So any fight with Ted and John is a Curb-Stomp Battle because John doesn't have the heart to trying to win. It's literally their friendship holding John back. And to boot, look at their fight in the hotel room. All it really is is the sort of childish roughhousing that kids do. John is basically just grabbing at Ted in anger without really doing much actually harmful offense. Teddy is mostly doing the same - throwing things, grabbing and slapping. It's only when actual harm is done - the TV - do they stop fighting. So at this point in the movie when he's being chased, Ted realizes this - he realizes that he's holding John back - and so he probably realizes that the two villains he's up against don't have the same reserve (they did rip an ear off after all) and they're not just roughhousing.