What do you mean by "LE"?
According to Wiki, it refers to the organization he might be talking about not connected to any organization.
Imagine authorities running a mixer to identify their so called criminals, that will be a disaster to any users who fan of using mixers.
I never heard that there is a legal mixer and I'm sure if there is a legal mixer there is a huge possibility that all transactions are being recorded and monitored.
That is why we need a mixer it's because we don't want other people to monitor or track our coins.