Just watched this (SPOILERS)

I enjoyed it for the most part - but I found it implausible that a woman would unlock a door to a man screaming angry abuse through it. Also the idea that she didn't give a moment's thought to being caught somewhere on CCTV was somewhat ingenuous. I don't think a city as large as London would ever be totally deserted - there is always someone around - the homeless - nightshift workers - roving gangs etc. She would have done better to have tipped the body over the railing in the beginning and made it look like there had been a fight in the apartment, but then there would have been no film!! She seemed to be a cool and collected customer and I think she could have outwitted the security guard with no problem had she put her mind to it. She could have seduced him and drugged him in the shack and then set light to it - two birds with one stone and more in keeping with her character - so yes - I felt the ending was a bit weak.