I almost couldn't believe the 8:41/last 3000, although nothing would seem impossible for Klosterhalfen.
No lap times on the official results, but found a Facebook livestream (Lange Laufnacht Karlsruhe, second to last live video).
The announcer says Klosterhalfen's 400 splits early on: (stream starts mid-race) ... 71 (2200-2600), 72 (2600-3000, this is where Klosterhalfen makes the break from Klein, who had been running with her), 68 (3000-3400, my estimate from the video), 68 (3400-3800, my estimate), 70 (3800-4200, estimate), 69 (4200-4600, estimate), 65 (4600-5000, estimate).
So, this was typed while watching... Last 2.000 m were 5:40, last 2800 m were 8:03. So 8:41 for the last 3000 m seems correct, if not even faster.
But the most impressive thing is watching how she just throws it down after 3000 and blows past everyone, only slowing down after crossing the line. Just wow.