Attacker (only) should be able to suggest agreements before the defender decides whether to flee. Once the defender suggests an agreement, he can't flee.
Upon further review of http://wolff.to/titan/errata.html, the defender is supposed to decide whether to flee before negotiations start. So this is invalid.
Attacker (only) should be able to suggest agreements before the defender decides whether to flee. Once the defender suggests an agreement, he can't flee.