The man who filmed the video of a knife-wielding man in south London said he couldn't believe that the man and acquaintance had not attempted to flee.
"I think he was there just for the police and the army guy," said the witness, who asked to remain anonymous.
"The time it was taking the police to come, that was 30 minutes, and in 30 minutes the guys could have run, take the train, gone anywhere," he said in an interview with ITV News.
A video in this entry has been removed for legal reasons. See part of the man's interview here.