Its true what it says in the article that the bank is in such a conspicuous position that it would be hard to make a swift getaway unnoticed.
As long as the staff were unharmed thats the main thing as they're all so nice in that branch.
Mind-You I once narrowly missed an armed raid at Barclays on Ladbroke Grove (they ran past as I was walking in!) And that branch is also on a corner with lots of passing foot and road traffic.