Tommy, I hope this is a wind up as I've never heard such a pile of tosh before. If this is true I would imagine they are using the DSC1 as an argument to prove your markmans ship and suitablity to take a safe clean shot. So what about the thousands of Fac holders who regularily shoot foxes with expanding ammo and have never stalked deer and have no intention of doing a DSC1. None of what you quote even meets with ACPO and Home Office guide lines.
I hope you challenged them.