There is some information there but not as much as last night. The Seattle fan who Boehm is working off has since protected his tweets. I read them last night and the guy was infuriated and a bit over the top, though perhaps understandably so. When DCU responded to him by saying they would look into it and asked for more info he basically told them to sod off. What I remember him alleging is that DCU security abandoned the Seattle supporters at the gate, and they were almost immediately set upon by by some DC supporters, that security saw this and didn't care or respond. They might have even said it's not their job once people leave the premises.
So it is fairly similar to the account of the Orlando attack. The main difference being I think the Orlando attack came further away from the stadium and security had even escorted the NYC contingent some blocks from the stadium before leaving them on their own, and all was quiet at that time.