I didn’t accuse your SIL or her college of elitism. I wrote that if you were right, and that being in good relationships with an alumnus interviewer increased the chances of a kid to be accepted, that would be elitism.
I was being skeptical of your take on the story, because it implied that the college engaged in elitist practices. Basically, I was saying that I didn’t believe that the behavior of that mother towards your SIL had any effect on her kid’s acceptance, and had your SIL interviewed her kid, her feeling towards the mother would not have affected the kid’s chances of acceptance. The reason that I believed that was specifically because I don’t believe that your SIL’s Alma Mater engages in elitist practices.