Yes the magic word:
LIABILITY

I believe they have this training, as believe it or not, many police recruits have never been in a fight or have gotten punched in the face. It is more like awareness, much like tear gas & pepper spray exposure. There have been other examples of this as well. Years back, the Mass Troopers had a similiar unfortunate occurance as well.

Defensive tactics are also taught to cover the agency for liability purposes as well. So it is a catch 22.

I also would not be surprised if there may have been some hazing or intimidation involved, to persuade someone to drop out, that the staff did not think would make a good officier.