So the deal in question was put together in 2003 by Terry Semel and for a while was very successful. By itself this deal got Yahoo Mexico to breakeven.
Accordingly, it appears the deal was still going along well after Semel left Yahoo, so now the question becomes which CEO botched the deal. Yang? - I doubt it. He was in over his head, but he wasn't messing around with the company.
Bartz? That is where I'd put my money. She's the CEO who famously (Infamously?) insulted Jack ma in front of his staff causing him to loose face and later steal AliPay. I don't doubt she told Yahoo partners to kiss-off - only she most likely did it using her colorful vulgar language.
Thompson. No, he wasn't around long enough.
MM. Again No, this thing had to be broken before she got to Yahoo.
So here is another Bartz mess, in my not so humble opinion.