Becker said always his loss to Muster in Monte Carlo was one of the worst in his career. Well, he lost the match after wasting matchpoints and it would have been his first title on clay. I don't remember anymore that he insulted Thomas afterwards, but let's not forget we didn't had internet back then and MTF, where we get to hear everything a player says and does these days
It's available and I will find the links for you. But Becker is an arsehole of the highest order.
I was there in the stadium that day and Broom Broom Becker wanted to be the hero and go for a 200km/h second serve and it missed, then after he lost that 4th set tiebreaker, he got mauled in the 5th.
Muster is also notable for the way he has adjusted his game to keep up with the younger generation of clay-courters, whose experience of only ever having played with graphite rackets - Muster goes back to the age of wooden frames - has made for a more aggressive game in which the ball is hit flatter and from not so deep.
But then Muster rarely misses a trick. Among a number of run-ins he has had with his fellow pros, not least with Boris Becker when the German all but accused him of taking drugs.