Greetings from the land of Torrilla! I am even more in awe of her given that Twitter, Tumblr and Google seem not to be working (blocked?). This site clearly too unimportant to attract the censor's attention...
My two pen'oth is that he probably went once, video was posted next day, and that the sighting with the blonde is genuine - insofar as that means anything. Without context it is hard to tell if being "with" someone is a correct assumption given that at the theatre half the people there are sitting next to a person they didn't go with. Maybe he struck up a conversation with a hot blonde he happened to be sitting next to, the dirty dog! And the stage door bods could be the people he actually went with, friends of Gatiss he met at the door or who knows what.