I'm not sure if that isn't a semantics thing, as 'Trent Junction' no longer exists, there being Trent South and Trent East Junctions. There's 2 possible scenarios to me: 1. NCE have fudged it slightly and Trent South Jn to Sheet Stores is included, no idea if Sheet Stores to Trent East would be too for ECS moves, or 2. There exist plans for a large-scale remodelling of the Trent Jns/Sheet Stores area and so a section has been omitted whilst further work is carried out.
Somebody may be able to add the various KMs up and work out how it all reckons against the MML mileages.