It actually is exactly that = one or two isolated incidents.I think it's fair to say that she was one of the biggest sore losers in the history of this sport; it wasn't one or two isolated incidents, it was day in and day out. Someone like Serena bothers to swallow her pride for a few moments and be nice to her opponent at the net, Graf giving a decent handshake after losing would basically be reason enough to stop the presses. So where does the notion that she's classy come from?
That's why you were able to provide a grand total of only one evidence.
Now if your claim is that Steffi wasn't flawless and classy all 100% of the time; in a lifetime of tennis court appearances — then hooray for you [insert Pelosi clap].
You have successfully proved that Steffi is human and therefore not perfect. Congratulations.