It's obviously an outlier with even just 1 anti-feat against it.
Dr. Flug needs a simple reason not to be an outlier in this case and we cannot comment without knowing the people who know this series, if there is no such reason, it would be an outlier for him to succeed beyond his power and potential.
For example; (DCEU) Batman being able to keep up with Superman and hurt him would obviously be an outlier because batman is between layers 10-8 while superman is between layers 5-6 and that is an outlier, but there is a reason why Batman is not an outlier and that is kryptonite (a highly powerful stone that helps weaken superman).
For dr. flug, I think this endurance achievement is treated as l2c and probably (by vsbw, of course I don't know about black hat), so we can say that inferring a probability from this means that you cannot know anything for sure about its truth or falsity unless the opposite happens. So if you say that something is absolutely true or false you are committing the fallacy of argument from ignorance.
Summary: In short, extraordinary claims require extraordinary evidence, and in this case extraordinary achievements require extraordinary potentials.
Taking l2c when it has a potential like tier 7... if they did such a thing without any justification, it is up to us to correct it.
But we can't provide that proof, someone who knows about the black line should tell us that.
By the way, if you agree with me, can you specify that "if there is no logic in taking l2c, it would be an outlier"