Evelyn,
I think Teacher was talking about his 400 -linked brakes- on any bike you should hold the rear brake if it locks up and ride the skide to a stop (unless you release the skid fast) . the front brake has to be released (real fast) or your going down.
On a linked break system if the front skids you still release front brake hand leaver pressure , and this should stop the skid as the left hand (linked to the front) will not lock up the front b4 the rear is locked.
NOTE -This does not work out on gravel, water ,ice & snow.
We all need to practice panic stops, those of us with linked brakes (400)need to understand there advantages and disadvantages