In my experience the main difference is that via the "Short Term Prospectus" the shares or warrants issued are tradable on an immediate basis where as a "Private Placement" has a hold period of usually 4 months plus a day.
So via the "Short Form Prospectus" many brokers sell off an existing position to buy into the offering and still have free trading shares immediately- and gain on a financial basis or through warrants.
So perhaps the big sellers will be buyers in a new offering???? If they are invited to participate as I believe this will be by "Invitation Only"
IMHO