How do you see the timer? I can't see one using Firefox.
That said, I didn't hear any Allahu akbars. It sounds much more like "come on up"
The sylabols don't match IMO. 1-2-3, 1-2-3 (come-on-up)compared to 1-2, 1-2, 1-2, 1-2 (al-la ak-bar, al-la ak-bar).
I certainly don't discount this act as a terrorism event though.