I was watching the video for Skrillex's Mumbai Power where he famously shows Izotope's Insight reading -3.7 LUFS for a short portion of the track before the second drop:
However, I purchased the FLAC for this track from prostudiomasters and measured the LUFS for the same portion of the track that Insight is open in the video and was surprised that it came out to -6.2 LUFS. I even used Insight as my analyzer to rule out any differences between analyzers. It doesn't seem like the track was simply turned down by 2.5 db in the FLAC because the sample peak is 0.0 db, the true peak is + 0.26 db and just eyeballing the waveform shows that these peaks aren't outliers and that the waveform is one fat sausage consistently eating up all of the headroom.
My going theory is that he mixes at about -4 LUFS and plays this version at shows (the EP this track was released on is called "Show Tracks" after all). Then, either he himself or someone else masters the track for platforms that are more accustomed to a standard -5 to -6 LUFS track. Is it possible to "decompress/upward compress/expand" a track by 2.5 LUFS in mastering? I did notice he has Ozone 5 after Insight in the video but he never opens it so I can't see what is in there.