I'm going to say it has more to do with Canadian distributor than HK not sending product when an order is placed and paid for.
I agree with this statement.
I don't know what your background in the Canadian firearms industry is, but I've worked at in manufacturing, retail, wholesale and importation / distribution for a total of a decade. I can tell you that your perception is incorrect. Having worked for one of the HK importer / distributors for Canada, the problem is most certainly with HK.
HK Germany basically doesn't care one bit about the retail firearms market, at least not Canada's. We tried to get HK to work with us to make some tweaks to the HK243 to get an NR classification, something that should have been pretty minor. They flat-out refused. Their explanation was that the rifle was already perfect and didn't need any modifications. So that went nowhere. We'd send regular emails asking for updates on our (long) list of backorders for rifles and pistols. Those would go unanswered. Instead, we'd get occasional emails from HK with a list of available pistols that they wanted to offload. It was pretty clear that these were overruns from other production orders, combined with old stock that they wanted to clear out. Every time this happened, the stuff on offer was not the stuff we had backordered months (or years) before. And it was hinted that if we passed on the stuff on offer, we'd probably miss out on the next round. So we'd end up with a vault full of SFP-9s that nobody was buying because the market was already saturated.
Trust me, we ordered USPs and Mk23s and USCs and SL-8s and other models that people actually wanted. HK just ignores it. They produce stuff for mil and LE contracts first, anything else is a distant second. They are practically impossible to communicate with. One major pistol order was nearly seized and destroyed by CBSA because HK sent the wrong magazines with the shipment. We tried desperately to get a hold of someone at HK to get approval for the shipment to be returned. Nearly
two weeks went by with no answer from HK. We tried emails and phone calls with no luck. As you can imagine, this is not a good situation for a business to be in with thousands and thousands of dollars of merchandise at stake. Eventually we just refused to accept the shipment and it went back to Oberndorf on HK's dime. Another week went by before we heard from our HK contact. Apparently they were out of office on vacation. No apology, no explanation beyond that. It took weeks for them to sort out the shipment and get it back to us.
I tried to get spare parts for customers. Apparently HK had considered us to be a warranty center - you'd think that meant they'd send us tools and parts to service their guns, but you'd be wrong. Every time I tried to get spares for customers, HK demanded serial numbers and a detailed reason for why I needed to order something. Did you lose your windage screw on your USP Tactical? Good luck. I'd email weekly asking for updates on my outstanding part requests. These would simply go unanswered. I tried to get HK to send us a number of common consumable items for popular HK pistols, things like magazine springs and followers, recoil springs, firing pins, extractors etc. These requests also went nowhere.
HK has a reputation for a reason. I always assumed it was a half-joking kind of thing until I actually had to deal with them on a B2B level. If anything, they are far worse than their reputation suggests. Keep in mind that we were a good customer - we paid on time and in full, and we were had placed orders for a number of SKUs, but HK simply didn't produce what we asked.