So to answer your question, no you cannot just dive at a corner like that from behind. Had they been alongside it would have been Logan's fault. But KMag was trailing by enough it was on him to back out of that bad idea for an attempted pass.
I just looked at it again, and I still disagree. KMag was quite a bit alongside even in the corner before the incident. His Frontwing was almost alongside Sargeants front wheel. Sargeant probably couldn't see him there but he has to expect KMag sticking with him through that complex.
Again, I know nothing of F1, so I hope I don't offend anyone. I know you need to protect the drivers, but it seems like allowing that maneuver, along with sensors letting drivers know that another car just dipped into their planned line, would make for more exciting racing. There's probably a legit reason this is not the way it is.
It's probably going to be ruled driver error by Logan, since it appears he is just completely unaware the other car was there. The move was aggressive but more space could have been left by Logan imo.