They lied. That should tell you everything you need to know:
The funds remain frozen at our addresses, and when the frozen funds are seized by the authorities, they are also sent from our addresses.
That's not true. You say the funds "remain frozen", but that can't be since you've
mixed them already.
The first transaction was mixed
in this transaction and that same output was used to
sent to another address. The second transaction was mixed
in this transaction and also
sent to another address.
None of the funds were frozen in your wallet, you're
normally using them to pay other people.
To summarize:
if those funds came from criminal activity as you claim, you've now sent it to other innocent users who now own those "tainted" Bitcoins.
It sounds very much like you only care about "taint" when it's convenient for you.