What controversial crowd control tactics by the Central Park Rangers?

From the movie "Elf"(2003) :

"Dick, uh, according to authorities, the area has been cleared. Only the central park rangers now remain in the park.These forces are highly trained, but rarely see action. Some have accused them of being too gung ho when called into duty, and their controversial crowd control tactics at the Simon and Garfunkel concert in '85 are still under investigation. "  Source

The Central Park rangers

The Simon and Garfunkel free concert drew a crowd of over half a million people and the Central Park Rangers were investigated for being a little "over-enthusiastic" in their methods of crowd control. (Source 1)

The Simon and Garfunkel free concert drew a crowd of over half a million people and the Central Park Rangers were investigated for violence during crowd control. (Source 2)

TBC..

Contact me if you know more about this, I am curious...

To finish off, here is a video from the concert: