"Maybe all five trains had entered the tunnel before the first one stalled? DUH!"
Something the author of the original article should have done was to estimate the actual length of time between the first train breaking down and the last train entering the tunnel, taking the perfectly sensible assumption that in order to get five trains into the tunnel the first must have got quite a long way through before expiring. I wouldn't be surprised if the time taken to get five trains beyond the point of no return was shorter than the delay loop in ascertaining a) that there was a problem and b) that it wasn't just related to a single train.
However, Eurostar do deserve a bucket of shit for this one, but for the passenger care response, not so much the railway operational side - in any case they're not actually a railway operator, they contract out the management of the service to an outfit called InterCapital and Regional Rail, in which the largest partner is National Express, along with SNCF, SNCB and British Airways. This explains why the Eurostar Board is full of people who are employed to run contracts and sales and marketing, not trains. Mind you, I'm not sure this multiplicity of entities is necessarily a great way to run a railroad, the only thing going for it is that it's not as mental as the original structure.