The "Dead in the Water" version of the raid is so straight forward, its no wonder they managed to solo it. There's literally no enemy that needs to be killed apart from the Strangler heart and that doesnt really count. My guess would be he used something like a Mr.Handy blade or a Ripper, Chainsaw since the heart only counts hits received in order to get damaged, not actual damage done.
This weeks raid seems to be a steep step up at first, but its quite managable once you figure it out and you can actually skip half of the whole thing if you are smart. I did it once on novice and twice on standard (once with couple seconds left and once with about a minute+), was too late and too tired to go for expert before writing this and going to sleep (EU).
Give it one or two days and it'll be no problem. The only thing that really annoys me is the forced need of PA (lets be realistic, Hazmat Suit is bullshit) and the lack of a guaranteed three star item at the end.
Gonna try for expert tomorrow and see how that goes but I need to farm materials for my plasma flamer and the mainframe cores first.
I was hoping for some other form of difficulty that doesnt involve time but all in all its a welcome step up in difficulty (until you get it down properly) from the dead in the water version.
The vault raids are more enjoyable than I thought they would be and I'm actually changing my whole build into a teamplay version since I really only do the raids now due to lack of other challenging content.