Re: sort of reminds me
According to the record on PeeringDB, they do peer at IXManchester (albeit only a 10G connection, piffling compared to dual 80G at LINX).
Given that they have a presence in Equinix Manchester Williams/Kilburn (MA1), they could presumably pick up some transit from a provider there as well.
Seems more likely (as per Alister's experience in Derby) that the fibres coming out of the affected DCs are all in the same duct for some distance, meaning that even with redundant/diverse links that (eventually) split off to go North/South, if you physically ding them between the DC and the split, you'll take out the lot...