Don't you find weird that this address has already been used 6 times since October? I don't think you can be "100% sure" that this wasn't a mistake on your end.
I think its actually quite convenient. If I was chipmixer and I was going to selectively scam people, this is exactly what I would do so people like you would say that. It's all about creating a scenario in which it looks "unrealistic" to get away with it. On the contrary, if someone went through all the trouble to try and trick me (whether getting a typo domain or whatever) why would it go to a place that isn't spent? I would just keep these unspent until my full complete exit scam.
Unrealistic theory fits when you are sure who is guilty and you want proofs to confirm it.
Your theory is - since October ChipMixer selectively scam users by serving special address before they decide how much they want to deposit. 5 out of 7 transactions to this address are under 3 mBTC. 1 transaction is even lower than 1 mBTC. All that while paying around 10 BTC (since October) for signature campaign at BCT.
More realistic theory is that you are using Tor while accessing .com:
Attention:At least one Tor exit node serves chipmixer.com as plain-text stripping SSL encryption and replacing deposit address with their own.
If you use Tor - please use Tor link:
http://chipmixerwzxtzbw.onion/ This message was posted in July.
More about Tor exit nodes:
https://medium.com/@nusenu/how-malicious-tor-relays-are-exploiting-users-in-2020-part-i-1097575c0cac