This seems plausible, and refreshingly free of the conspiracy theories already being bandied about here. Though my impression, after seeing the various videos, was that Cristina had no idea what was happening, she seems to wave something away (maybe compressed air) and just act confused.
At least the comments here haven't descended to the level of the followers of miserable pamphlets like Clarin (sample comment regarding the gunman: "tenia una sola tarea"). But the conspiracy theories and distractions are enough. Given that Cristina wanted to meet her supporters, more police wouldn't help, nor barriers, only close protection bodyguards (who were certainly not awake to the possibility of something like this happening). And in at least one of the videos you can hear shouts of "Matálo", so, yes, the gunman was in some danger of being lynched.