Well, he dissed the mighty dollar--TBs, actually--on June 23 1997 in a speech that he gave at Columbia University, causing a lurch in the US financial market.
I'm sure that the US authorities must have been hating mightily on Japan with NYT and WaPo writers between then and September 12.

In any case, by June 1998, the economy had tanked, securities giant Yamaichi had collapsed, and Hashimoto had to abandon his fiscal reform program only a few months after its incipience. (The LDP would the upper house election and Hashimoto would resign as prime minister on July 30.) This against a backdrop of Bill Clinton's balanced budgets and the IT-driven economic boom, which should have primed the U.S. media for Hashimoto bashing.

No smoking gun, though I hope it helped.