the guy DID run, not only did he run but he ran onto the underground. That's the underground, the same underground that some group of shit heads blew up a few days before.
He ran because his visa was invalid, rather than following the clear instructions of the police officer to lay down with his hands behind his head; do I think he was foolish? damn right, do I think he deserved what happened? of course not, his life is of as much value as any other regardless of his actions.
I think the police reaction was way over the top but clearly understandable given the circumstances. The police were watching the house where he was staying, not knowing that it was subdivided, thinking that he was linked to the bombers in the same building. Had he not ran onto the underground and given the impression of being a threat to the public then he wouldn't have been shot in the head
It is very easy to second guess the security agencies but they are working with very limited information against a well organised and financed group of people. The fact that the second group managed to get into position and were only foiled by duff explosives shows the pressure that the police were under to do SOMETHING to avoid a further attack and reassure the public.
The arrests of the guys who carried out the failed attacks without s single shot being fired shows that lessons were learnt from the Menezes mistake