See with such a beautifully thought out strategy I must interject on behalf of the man. Firstly I believe the issue of IIED is subjective and completely dependent on circumstantial evidence. It can not be proven beyond a reasonable doubt that he did it on purpose to inflict pain. There can be a host of other reasons, which are equally likely and plausible.
Secondly the comment stating that the fiance was telling all his friends he was going to break up with her is hearsay and thus should be inadmissible in court. The friends can be brought to the witness stand but till they give their testimony the comments are in fact hearsay, and not admissible as evidence and thus should not be the basis for the claim. You can’t make a claim on something that can not be substantiated.
Now on to the BOP. It stands to reason if she had heard rumors that he was not gonna marry her and even then believed him, she is partly to blame. She knowingly accepted his deceit while others were stating that he does not plan to marry her. Even when she heard these rumors and the comments she continued to spend extravagantly without any hesitation. That does place some blame on the lass and leads to the issue of IIED. She had reasonable doubt about his intentions yet she went ahead with all her plans. Pretty self-destructive.