Haven't read the 100 pages, but reports on tv last night suggested the gates already had an auto lock device which had failed. The girls waited for a train to pass, then crossed, only go be hit by a second train.
As always with these things it's hard for those experienced in life to understand such oddities. Two youngsters less experienced in life wouldn't necessarily fully understand.
You do have kids yourself, although much younger would they understand precisely what to do? And if they did would they cheat the system, play a dare, mess about on the tracks?... Or think the coast was clear and cross perhaps? The gates have to account for ALL pedestrians... No?
I did play on a crossing as a lad, slightly unaware of where and what a local lad had in mind as we where on the way to another lads house, we arrived at a pedestrian crossing with a style either side. That was it. He was having great fun placing coins on the track so the train would flatten them. The drivers couldn't see the coin obviously but the look on their faces was telling as they passed us at the side inside the boundary. They where bloody petrified.
Kids don't get the rules, and if they do, love to brake them without understanding the dangers. I guess Network rail have a responsibility to pedestrians at that crossing, and failed in that responsibility. No real suprise it seems to me, but then I don't have all the facts and haven't read the report....