However it did appear that they used NBC roof top space.
I'd trust your judgment on this over mine, but it looked to me to be very similar to the rooftop space they'd used previously, and about in line with the angle from the Sky (Fox) bureau in DC, which is down the road from the Capitol.
Either way, it's presumably only a matter of time. Sky (with Fox) in DC will have a similar situation to NBC (with ITN) in London. Contracts, leases, technical issues, contractual places of work .. it'll take a long time to make changes to that, and right now with perfectly good existing contracts and office spaces budgeted and paid for, there may be no practical or financial advantages.
And anyone commenting "Comcast will sort that out" needs to cool down... They've been owners for 10 minutes, it's clear that they want Sky to run itself, and Sky News was *the* lightning rod issue for the entire Sky takeover, with undertakings given by Comcast about its independence. That doesn't mean they won't do anything with it ever, but I cannot for a moment think one of their first moves will be to start interfering with the channel.