There is no ambiguity as to source or destination at all. If you send me a coin I can see where that coin came from and where it came from before that. Likewise if I send you a coin I can see when and where you spent. If I've ever dealt with those people (or do in the future) I will likely see the relevant connections as coins are combined and change is returned. If I happen to be a large economic actor such as an exchange, payment processor, etc. I may well have dealt with a huge number of participants and be able to identify many of them.

I'm pretty sure there is a thread on bitsharestalk or whatever your forum is called where bytemaster explains this and acknowledges that TITAN isn't really intended as a full anonymity solution but more of user-friendly incremental improvement over reused addresses. I've seen that thread before but I couldn't find it just now.