John vote would have been big last week due to the behaviour of the judges. Even suporters of other dancers were still throwing a vote to John, so Im sure he spiked, I have read 40%, 50%, 62%, this would have died down. The underdog always gets a sympathy vote, just the judges over reacted, which gives the public more to feel sorry about.
If it had been left to run its course, without the judges adding fuel to the fire it would have died off and John would have been voted off.