Blue Triangle empty run on the North Circular

[Watershed]

I was rather surprised to see a Blue Triangle electric double decker, running empty eastbound, on the North Circular near Neasden, a couple of minutes ago.

From bustimes.org it would appear it was operating route 129 services today between Lewisham and Gallions Reach, finishing its last in-service run at 20:43 in Lewisham. So how could it possibly make it it to Neasden in the space of 20 minutes, let alone then be heading back eastbound on the North Circular?

In any case, why would a Blue Triangle bus be riding around this part of London, well outside their 'patch'? Am I missing something obvious or is the tracking info about earlier journeys wrong?

Thanks in advance. I don't take a huge interest in buses but this piqued my interest.

 

[dodecahedron67]

It looks like that bus wasn’t actually in service yesterday, but today has been used for a school service in Romford, followed by a dead run back to the Docklands as seen here

 

[Watershed]

Ah sorry, yes - looks like I was mistaken and looked at Friday's timings. So it was somewhere out west heading back towards Romford over the weekend, perhaps on an RRB job?

 

[700007]

The 129 buses are regularly out on Twickenham Rugby Shuttles and West London Piccadilly line rail replacement services when they're on. Unsure if they were on the weekend just gone but it might answer why one was in Neasden.

It may also have possibly been visiting BYD Heston for routine maintenance work as well?