The panel is set to hand down its sanctions for each officer on Friday.
The hearing concerned former Sgt Luke Thomas, former acting Sgt Luke Allen, former PC Kelsey Buchan, former PC Carlo Francisco, former PC Lee South, former PC Darren Jenner, PC Glynn Rees, and "Officer B", who has been granted anonymity.
The panel found the eight officers had also failed to challenge other group members' conduct.