The 800 De La Gauchetiere Branch︀ in Montreal has a lot of chinese clients, probably more than any other in the︁ city. They are used randoms showing up with millions in unexplained wire transfers. They are︂ more scared about obvious AML risks like smurfing/e-transfer movements for canadians/etc than a rich guy︃ who showed up with a ready-to-serve story to alleviate any concerns and to be frank,︄ Canada runs on criminal money. Without it the country sinks into the abyss, the banks︅ know it too so if you're having a very high turnover/deposits coming in they won't︆ question you as much. They close accounts of students trying to buy $2000 in bitcoin︇ however, that's a major risk in their books (lol).
EPB probably was playing with a︈ f**k load of cash and they also probably lied with their nature of business/operations to︉ bypass compliance checks. A shell bank doing forgery/cooking the books to appear more legitimate than︊ they are is not uncommon and compliance checks in Canada are basically university grads pulling︋ 45k/year doing most of the work so i doubt the quality of the checks are︌ of high standard or anything serious to begin with. Financial Intelligence Units at banks there︍ only deal with known/suspected cases of fraud, not with new clients or onboarding. It's very︎ easy for a serious operation to bypass these checks and get onboarded as long as️ the transactional profile of the client doesn't ring any red flags.
For BMO it's simple: No red flags spotted + a lot of cash coming in = good client no questions asked.
Some even go as far as getting an MSB license from Fintrac to pass onboarding more easily (An MSB license is a clown license, anyone can get it, but to canadian banks it shows you are "regulated").