1. Pheonix definitly cannot "win" by "proving Makoto guilty". The scenario is another "final case of Justice for All" or "second-to-last case of Spirit of Justice", where Pheonix is pressured/threatened into taking on a case by someone though unlike those cases, not only is the goal set for him to prove someone else guilty rather than defend someone, but he also is doing this just for protecting himself rather than for protecting someone dear to him. Under these conditions, I suspect that Phoenix would:
a) Rather die than go through with it leading to Makoto to win by default, or
b) Pretend to go along and attempt to use the trial to expose his blackmailer somehow, without intention of actually declaring Makoto guilty
2. If 1.b) applies, then there is a good chance for the situation to be turned around with both cooperating to prosecute the "real mastermind" instead which would be an incon, I guess, regardless of whether they succeed or not.
3. Even if Phoenix begrudingly decided to prosecute Makoto, his motivation would be at an all-time bottom and there is no way he'd succeed like that.
Based on this it's either a victory for Makoto if Phoenix refuses the fight itself or if he begrudgingly tries to go after Makoto, or an inconclusive if Phoenix tries to go for the real mastermind instead. Or to put it another way, I just can't see any scenario where Phoenix actually wins.
Not voting yet though.