What really came to mind in your story was ,how bad at his job the guard was he should really be inconspicuous so as not to be noticed watching ,well not so as it is blatantly obvious . When I used to work in a fruit & veg shop many moons ago the gaffers wife taught me that you should watch but not be noticed at least as much as possible .,How much repeat custom will that store get ,if the guard does not change his methods ?
He was real bad. Like bad comedy sketch bad! It was painful!