I'd suggest if Mr Skymonster travelled on 25/05/12, the MML was a bit of a state due to the wires being down in the Harpenden area, as well as heat related emergency speed restrictions, with ticketing restrictions removed, and other issues like crews being out of place due to heavily delayed and cancelled trains - unfortunately I doubt catering crews are a priority in terms of keeping trains moving if you have a driver and guard available to take a train. Again if revenue restrictions are removed, it's unlikely that the train manager is going to concentrate on revenue duties. It's entirely possible that gateline staff had been deployed to other duties that are more important than revenue protection during severe disruption particularly at St Pancras, where FCC Thameslink services would also have been well disrupted for the whole evening peak as well as the afternoon and evening - I believe it kicked off fairly early on.
From what I've seen, revenue protection at St Pancras is normally very good with a well staffed gateline, I haven't seen much of Nottingham to comment.
With the various issues that were going on and the number of delays, cancellations, set swaps, crew swaps etc that were occurring, I very much doubt that First Class complimentary snacks were going to be anywhere near the top of the controller's priority lists - they'd be more thinking about the basics to provide a train to get you home on.
Overall Friday was not a good day for the MML it seems so I don't think it's fair to judge the service on it, particularly as Skymonster says himself it's normally pretty good.