In the domain industry, that's par for the course. You can almost never get 'proof' of what they are doing. You can just see patterns and changes. You can hypothesize based on trying something again and again, manipulating the inputs and seeing what changes. Sounds a bit like a science experiment? Often seems that way. There's a ton of NDAs going to all sorts of people and companies to do different stuff. The inner workings of a lot of stuff is never legally allowed to be talked about publicly. So you end up with this type of hypothesis.

The actual transfer process can be nearly instant given the EPP code and the registrar's permission. What happens in between is somewhat fuzzy and I am not sure there are clear rules on how each company handles it. The longest I've seen (that I recall) is 7 days, but I could be wrong.