Neil, thanks for the get well wishes - it happened this past Monday, so it'll take a while...
I see your point regarding general need for precaution. I'm not familiar with the Clapham station. Part of the problem at Gare du Nord may be that with a heavy large suitcase in front - a common scenario on Eurostar - the line of sight to the gap may be blocked. And cautioning passengers as they disembark seems to require just be a procedural change, as Eurostar already has the staff on board to man the exits (at least this was my impression).
I see your point regarding general need for precaution. I'm not familiar with the Clapham station. Part of the problem at Gare du Nord may be that with a heavy large suitcase in front - a common scenario on Eurostar - the line of sight to the gap may be blocked. And cautioning passengers as they disembark seems to require just be a procedural change, as Eurostar already has the staff on board to man the exits (at least this was my impression).