The only thing these people needed to pay attention to was not to be photographed while they were fighting. That was because when they fought, their masks were likely to be taken off, and they might also be injured. If their information was captured by the surveillance cameras making their faces known and people knew where they were injured, even if the authorities were tracking them based on their features, it would be very disadvantageous for them while they make their escape.
These people seemed as though they were not cautious enough, but in fact, they were very professional! They did not waste any more time arranging other things. After killing, they would leave. What they pursued was speed!