My first feeling was Rogh-legged too. I t was the white-cream head contrasting with a dark-brownish-blackish body that gave this impression.
Then I thought: it looks too big for this, it seems a huge bird. And then I realized, that its a very low resolution picture with much, extremly bad artefacts (all in one picture). As allways no offense, Marius, I just want to explain, why this picture is unIdable to me, even in quiz-modus.
But I hope for others to jump in, so I can learn!
It’s not just the colour pattern that makes me think RLB - the rounded large head looks very buteo and it has quite a full bellied appearance (which is darker than the chest from what little can be seen). It appears to be preening (in the second image with bill tucked in) so I am thinking this is distorting the outline shape - with perhaps the shoulder of the near wing drooping)
Not saying it is definitely a RLB but it wasn’t just the colour that gave me this impression - I can’t see how any accurate assessment can be made of size but it certainly isnt a vulture with a head that size!
If its an escaped bird of prey, than maybe its a good idea to visit the area again.
But the main reason to answer is to thank all, for the fast answer to my question: "But I hope for others to jump in, so I can learn!"
Debs answer is a good example for a detailed explanation, why she good the feeling of a Rough-legged buzzard, very educational when comparing to the pictures.
And thank you to dantheman and butty, too, and when Tom says, its unidable to him, than I give up. Thank you, Tom, too!