I've shown the images to Dick Forsman and these are his thoughts.
"... a first-summer Pallid Harrier male, in a rather typical plumage for the season showing all the main features of the species.
However, there are some inconsistencies with this bird, and it reminds me of some of the Pallid x Hen Harrier hybrids that we get here occasionally: The wing formula shows a rather prominent although short 5th finger (counting inwards from the outermost), which should not protrude like this in Pallid (creating a wing-formula normally seen in hybrids). There is also too much white around the eye (more like in Hen) and the faint streaks on the breast-sides, if belonging to the juvenile plumage, are also not good for a pure Pallid, but indicate possible hybrid origin. In other words it could also be a hybrid or intergrade between Pallid and Hen, or possibly even between Pallid and Pied, which has never been documented before to my knowledge.
The images are very good, so studying them with some more time might reveal some additional clues."
Eric