First, nobody has the right to two seats, one to sit in and one to put their feet on. BUT, if one person is sitting in a quad of four seats with the double seats facing each other, it is obnoxious to sit down directly across from the woman who was already there, knee to knee, when she could have sat down catty corner (diagonally) across from her in that empty seat instead. However, when the second woman did sit directly across from the first woman, the first woman should not have put her feet anywhere near the second woman.
IMO, there was no assault, no reason to call the police, no reason to put either woman off the train. They were both obnoxious, inconsiderate and stubborn. And I can’t help wondering weather the second woman was just looking to set up a situation that she could make a tik tok of.
It is totally possible for two strangers to share a quad of seats peacefully and comfortably. I’ve done it myself many times.