There is a fee for anonymizing.
If he received the 1 BTC bonus, it means that the transaction was free. In this case, the anonymizer only subtract the 0.0002 miner fee from what you receive. He should have received 3.458087223 in addition to his 196.54171277.
Are there any fees for anonymous transactions?
The base fee for anonymous transactions is 1.5% fee + 0.0002 BTC miners' fee.
From what I understand the bonus is for ppl who provide clean coins to the mixer
The way to provide coins to the mixer is to send them through the mixer. Then there are (supposedly) no fees and 0.5% bonus.
Which is how it worked for my 1BTC transaction. For the big one the missing 3.458087223 is actually more than 1.5% (which is 3)
but the fee should not apply anyway.
From what I understand, if the mixer is requested to transfer X coins it needs at least X "clean" (=just different, unrelated coins)
to perform it. If it doesn't have X coins it asks them from others and offering 0.5% bonus. Since he charges 1.5% from X he makes profit anyway.