My worst is ever so painful. A Scarlet Tanager in the UK, views not quite good enough to completely rule out Summer!
Despite hearing its distinctive call overhead and seeing movement on numerous occasions
Suppose your right Jan. Unticked
Common buzzard would have been an obvious candidate given they are common round here these days but the shape was wrong and there was no v-shaped wing despite the fact that the bird was gliding.
I have never had a good view of goshawk but saw one flying over The Lodge at Sandy a few years ago. I would not have counted it but for the fact that it was being mobbed by a very brave sparrowhawk at the time.
What time of year was this? I ask, as female Sparrowhawks are larger than males, usually markedly so, and some aspects of display could be mistaken for mobbing. That said, I suppose a Sparrowhawk could mob a Goshawk, as a potential threat.
I have been spending a lot of time looking at Common Buzzards this month, and, to a lesser extent, last spring/summer, and it is certainly possible for birds to glide for some time without their wings being raised in a 'v'. Indeed, juveniles (and birds intruding in the territory of a pair) regularly adopt a flatter-winged posture than one would expect. Juveniles also have a different shape to adults, somewhat, often appearing longer-tailed and narrower-winged, but this is hardly an obvious difference much of the time.
That said, your bird may well have been a Honey-buzzard, but, as you yourself were unsure anyway due to the nature of the views, we will never know for certain.
I would not dream of counting it anyway and it has to be one that got away but ...
Having just returned from a 3 week birdwatching trip in North West India we have about 20 birds that the guide pointed out to us but that we did not get good enough views ourselves to give them a tick. Particularly frustrating was a possible grey sided bush warbler which gave us great views of all of him apart from his side!!