I`m confused.What am i missing here?

Maybe contributor got a release (unlikely).

Also beats me how this got through as commercial. 

Release for property, but you're right this is strange.

People on foreground are somewhat identifiable. Difficult to see but there appears to be ads next to the grounds, sure.

Not sure how this got through QC as commercial. I can see (Google Reverse Images) it's been licensed many many times commercially.

Looking at the image number, it's been online for a long time. In the early days none of the stock sites worried so much about releases, I guess until they started getting treats of lawsuits.

Rules change for new uploads, but the sites don't worry too much about the old stuff unless they know that the subject is likely to be problematic. So people who got approved images before the tightening of the rules, are lucky that they have a monopoly but are also more at risk of the stock sites holding them responsible in the event of a claim.