Even with my one-powder-on-the-bench I've caught myself making mistakes in returning powder to the wrong bottle in a moment of 'impression' that I was working with a different powder than I really was.
Pharmacists have a system of checks that make it difficult to mistakenly fill a prescription. Even so, I just had to return a prescription with the wrong pills in it. Filling prescriptions or reloading, the consequences of mistakes can be bad to fatal.
Thanks for having the guts to tell this story. I feel that I need constant reminders of what I can do that's wrong.
PS: Sorry about your rifle.