No it is not. The stagger is to the break line - not carried through the path that the runner in lane 6 has to take to get to lane 1.
If it is a two corner stagger - it is not a two corner plus.
So compare lane 1 who has to run 50 meters to cover 50 meters. The runner in lane 6 is at least 5 meters out from that runner. If he takes the longest possible time to merge he will spread the 5 meters out over the entire 50 meters.
The distance he has to cover is 50.249 meters to go 50 meters down the track. That is just less than ten inches. Doesn't seem like much - but try sending someone after a world record and then add 10 inches onto the distance.
And I still contend that the altering in pace by changing levels is a handicap compared to someone who runs on the level.
But I do agree that running the wider turn is an advantage from a mechanics standpoint.
Bottom line - I haven't seen anyone else run the time he did under any indoor circumstances and they're welcome to try.