Not many came out after 55 seconds; those that did may have been cabin crew. In any case, the statement about 55 seconds can show that, in fact, the "industry norm" of 90 seconds (with half the doors inop) is inadequate.
As for Unterlinden, the point wasn't just that there was plenty of fault to be distributed, and not just the ATC, but rather that inaccurate popular media portrayals of the fault fueled the misery. Similarly, saying that "The jerk in 4C killed 5 people by grabbing his bag" will have real-world consequences. With smartphones, someone's going to have the grim task of sorting through all the onboard video/audio and assessing the evacuation.