I'm very sad to see this beautiful young lady in this video of the CCTV footage and my heart goes out to her husband and family as I fear the worst has happened to her. I just hope I'm wrong.
The body language in the video is something I can only look at through my own filter of personal experience, but what I see is quite a street wise woman realising she is in trouble. Personally, if I
felt threatened without any real evidence of immediate threat, the last thing I would do is show my fear. I would use my mobile to buy some time while I try to get a handle on what's going on around me and in this instance, I'd stop walking to help reveal the intentions of a passerby. If someone stopped with me or ahead of me like BH does, I would hesitate as well. If it was me, I wouldn't phone someone who I thought was asleep and unlikely to talk (husband), I'd phone someone who was likely awake and would engage in conversation with me. I still would not reveal my fear to anyone, unless there was evidence of an immediate threat. This is why I don't believe BH points a gun at Gillian, it seems more likely to be a phone to me.
We see more hesitation from Gillian when she appears to walk out of sight for the last time, in fact she stops again (as mentioned by DrWatson earlier on). It made me sad to read reports stating that she and the man then left "together" after the interaction, as if it were her will!
When BH and Gillian first come into view, on the right hand side of the shop front, I think he has just caught up with her after running. This would tie in with the man walking ahead of them who turns to watch what is happening behind him. It is very hard to run without making noise and I sure would notice, especially in that area at that time! Gillian appears to be taken aback by him and I definitely see her trying to distance herself from him. Poor Gillian, my heart breaks for her watching this! I so, so hope I'm wrong.