Looks like East Coast provided many more services between Leeds and Harrogate than was expected in the timetable.
With the benefit of hindsight, Northern probably should have run all services on the Harrogate line with loco hauled stock today, freeing up DMUs to ensure all services into Leeds from elsewhere this morning were double units, so at least so the public can see that more capacity was being provided, even if it still wasn't enough.
I think it just annoys the public when they commute every day during the week on a double unit and then turned up this morning to a single unit, it winds them up regardless of the logistics involved.
Services outside of Yorkshire would therefore be short formed as a result, but it would be less of a PR disaster if shoppers in Liverpool or somewhere were disrupted on this occasion.
Could East Coast have helped out more, do they have spare HSTs on a Sunday? How about Crosscountry's HSTs that are famously underused?