Understand your point of view. Agree it would be extremely simple to identify outliers in their data, this is what puzzles me the most though.
If the product manager had an issue with it, why didn't they mitigate their losses by closing accounts 2 years ago when people started the activity?
I see two options:
1) They were aware of the low-value transactions and gave their implicit approval by taking no action, or
2) They were grossly incompetent and asleep at the wheel.
I personally don't see an issue with what others have done up until their accounts were closed in September. However, I don't approve of the more recent activity of stashing accidentally credited points since the September closures. It's clearly an error on BW's behalf and as such attempts to prevent clawbacks are in a sense theft as the recipient is aware they are not entitled to them but retaining them anyway.