I think you missed the point of the article. It is not about minimizing Police attention but to minimize automated detection. That in turn will maximize amount of time/money that would have to be spend to backtrack you. You may stand out in some crowd and maybe easy to fallow visually by a human (eather on camera or in person), but (at current technology) imposible to load the image in to computer and say "show me where this person has been in the past week, month, year".
The biggest issue with cameras in London, is not that you are being watched now but that the the data is stored and at the later time, with help of facial recognition, easily, cheeply backtrack. It is just too expansive to throw people to review few hundred thousand cameras going even just a month back to create a profile of your movement even if you do standout.