Paul did not have the benefit of observing Jesus in ministry: a ministry that often befuddled the twelve in relationship to dealing with women - including that Samaritan woman. Jesus frustrated those most committed to "the Law".
When facing a situation with women, Paul seems to draw on his familiarity with "the Law", more than Jesus' model. That seems normal, but maybe different than Jesus indicated He might have done.
On the other hand, Paul was the champion of non-Jews - which a person most committed to OT Law probably would not have been. In fact, Peter, who had that three year mentoring, seemed to hang on to "Jewish only" Christianity longer than Paul.
This set of observations was made by the women students in an introduction to the Bible class I teach. I love watching people with little Bible background make exciting discoveries. If nothing else, people who had only heard that Paul was unreasonable discovered him in a new light.