If controlled goods were released onto civvie street, then someone broke the regs - therefore there was illegal activity. Simple as that. Someone didn't do their job, whether it was the person who was issued CADPAT selling it to a surplus store, or a supply tech selling a bin of stuff to a surplus store, or the person who was supposed to burn a bin of CADPAT clothing diverting it to a surplus store. Someone broke the law. There's no legal way for it to find its way onto civvie street.
Again, nice to be able to parcel it all up like that and tie with with a bow -- but mistakes occur, paperwork gets lost, stuff gets put in the wrong bin and it winds up on civvy street buried in a triwall of...DND pillowcases. In fact, if you take the sheer scale of issue and just start factoring in the law of averages tempered with a bit of Murphy's Law -- you'd be forced to accept that the kit's going to make it out on civvie street.
You're also injecting a lot of...intent...in your reply which just isn't there. "Never ascribe to malice what can adequately be attributed to stupidity"; i.e., never assume purposeful criminal activity when the background level of general cluelessness (or simple overwork/ understaffed/ overwhelmed) provides all of means, motive and opportunity. MPs and Various Other Agencies have realized that too, which is why the de facto rule with regard to CADPAT has silently changed to, "not illegal to own - but illegal to very obviously flog on Ebay or in Airsoft forums and force us to do something about it given current written regs."
So, now picture yourself as the MP having to go around and visit all these surplus dealers who are selling CADPAT to cadets or ravers or whomever else.
"Where did you get this?" Mr. MP asks.
"Where I usually get it...CADC national sealed bid," answers the proprietor.
"Do you have a receipt?" the intrepid investigator continues.
"Why yes...yes I do...' One lot, scrap textiles, CFB Petawawa, 430 kgs," answers the surplus store owner.
And in that lot there were four triwalls of air force coveralls, one triwall of lingerie'd CF combats, one load of brand new ICES parkas etc. in green, and beneath a stack of fleeces in the remaining three triwalls was more arid and temperate CADPAT than you could shake a stick at. All 'scrap textiles'. All legally purchased. Did some ASU bin rat make a huge mistake? Sure. Was it a criminal mistake? Maybe. Was it the surplus store owner's criminal mistake - or perhaps CADC's? Or ASU's? Who gets to decide that?
My scenario there happens several times a year despite best intentions and regulations because someone, somewhere in the supply chain will make a mistake. They have to. They're human. The Law of Averages demands it.
(I know of lots of stuff that got out that very way, though my specific example is a composite of a few of them.)