I don't know the source of that other info but this is taken directly from IMSA's T&S pages. People can interpret it any way they like but Lap 38 was the last lap under yellow, lap 39 the first under green, after the second long yellow to clean up after the Park Place Porsche hit the tires.
Cars are listed in running order; the only change I see is Oz Negri gaining one place in Ryan Dalziel, I had detailed notes but through a mistake in saving them deleted them, but I don't recall anything except Negri making a pass---I don't recall Dalziel sliding around or spinning his tires, but obviously if he couldn't put power down, Negri would have an edge. However, Negri never passed Pla.
In fact the only changes in running order until lap 57 (end of race) involved Barbosa bumping past Taylor, flatting, spinning, and ending up sixth.