Haffner is my #2 suspect. Now this is not a theory, but an observation. Maybe some of you can share your insights on this. 

Lisbon dos not share important pieces of information with Jane (whereas she gets angry when Jane does not share information with her) or at least there are are some things she has not shared with Jane on camera. There are two things she has not shared with Jane (I may be wrong about the first one, so correct me if I am wrong). 

1) She has not told Jane that Haffner is a member of Visualize

2) She did not think it was important to tell Jane that Haffner visited her in the hospital

We could assume that she did share this info with Jane, but not on the show. That actually seems more plausible than suggesting that she does not think it is important to tell him these things about a man who is on his list or that she is hiding information. 

Or is it?