Re: Not THAT realistic
You did read the bit about how the perp did _not_ have the faux firearm in his hip pocket as the photo shows. It was found during a routine security check. Perhaps whilst x-raying his carryon luggage? We don't know actually.
Stansted (no spellcheck, it's not stagnated) does tell people[1] that toy guns and replica weapons may not be carried in hand luggage, although if you saw the whole thing[2] in an x-ray, instead of just part of it, maybe you wouldn't be nearly as quick to pop a few rounds into the twit. Or maybe you would!
[1] http://www.stanstedairport.com/at-the-airport/security/hand-baggage/
[2] http://www.telegraph.co.uk/content/dam/news/2016/07/07/102660472-iphone-NEWS-large_trans++rXQPXGvM58CJoUBPwmOnP8ZizxpLuZqzh9z0a2I7-Dw.jpg