The reviewer may not exactly be a Johnlocker, but is certainly aware of the subtext. See what he says about the dancing...

Reviewer makes a good point about how Sherlock could easily have used his abilities to come up with ways to break up Mary and John:

http://www.digitalspy.com/british-tv/s129/sherlock/recaps/a541143/sherlock-series-3-the-sign-of-three-recap-the-end-of-an-era.html