^ Although it wasn't reported by the press at the time, dancer Zoe Birkett of the show was later interviewed by some published, obscure British press (including an interview earlier this year), and confirmed that Michael had attended the Hammersmith Apollo show. In 2007, this show was on May 22nd, which was when Michael was in the area.
This year, the show at the same location (as referenced by the YouTube posted) would've been May 15th. Michael was spotted watching Chronicles of Narnia in Vegas on May 16th, so if he did attend it would've had to have been a very rushed trip back, although with Michael anything is possible!
I find it very unlikely that anyone would go through the extremes of faking this entire MJ arrival just to post a five second clip on YouTube. Seems legit to me, it's only the date that I'm not entirely so sure of.