Was Justin Bieber's Reaction Towards This Irish Fan Not Perfectly Reasonable?

In a shock move, Canadian pop-git Justin Bieber acted in a justifiable and reasonable manner when approached by an overly-pushy fan.
Bieber was walking down Grafton Street when he was approached by an enthusiastic, phone-wielding fan.
Despite being warned off by Beiber's imposing bodyguard the cameraman persisted in badgering and harassing Beiber down the length of Grafton Street.
The Canadian singer wasn't impressed, giving the insistent fan the cold shoulder.
Several news outlets have reported on Beiber as behaving in an 'aggressive' manner. However if you watch the video you can see that Bieber, though kurt, isn't acting in an anti-social way whatsoever. The chart-topping musician has a reputation for behaving in somewhat alarming ways when provoked, he behaved himself this time.
The phone-wielding fan, despite being told to leave Beiber be several times continued to pursue him. Completely justifying the icy response from the musical of the Great White North.
The owner of the video, Keith Casey, took offence to Bieber's icy demeanour adding hash tags saying 'Never meet your heroes' and 'twat' to the video post.
In an interview with the Irish Independent Casey stated:
"I'm just in shock. It's not everyday a normal Irish person sees their idol in a sunbed shop and then they treat them with that attitude. Its just not fair. I was the only one who knew it was him. It's not like he was being mobbed. I'm just in shock."
Bieber is playing is playing a show in Dublin 3Arena tonight as part of his purpose world tour.