This so called "test" is pretty much an uncontrolled experiment. To be fair there should be another group consisting of non-Caucasian photographers carrying a large backpack and wearing a hooded jacket.
reminded me of an incident that i witnessed a few weeks back.
it was a saturday, I was at raffles place mrt station, waiting for a friend near the control station, where we planned to take pictures of the NDP rehearsal fireworks.
while i was waiting, saw that there are also a few photographers waiting around(can easily spot them with their tripods and dslr bags).
then saw this guy, whipped out his 5D MarkII, put on a tele-converter and a superzoom L lens and started testing or whatever, snapping away.
obviously grabbed alot of attention from the surrounding, since he's right infront of the control station with his camera and huge long white lens.
He kept on with his thing until he was spotted by the police patrol(the usual ones the we usually see patrolling the mrt stations and trains), they approached him and questioned what he was doing.
It went on for 5mins or so i think then my friend reached and we left before i could see the outcome.