Officers used a high dose of sedative to restrain the man after he continued "thrashing about'' in spite of being tasered twice by police.
"The man's momentum at the time was of such magnitude that the Taser prongs detached from his body. He immediately recovered and police had to use the Taser a second time - with much more success.''
He was taken into custody using "special safety restraint equipment''.
Knights, who lives Perth where he works in the mines, is due to return to the court in January for a defended hearing.
The assault charges carry a maximum sentence of six months in prison.
Knights was granted bail without any conditions.