Yeah pretty sure that’s a war crime under the Rome Statute. Emphasis mine.
The law applicable in international armed conflict forbids “mak[ing] improper use of … the military insignia and uniform of the enemy …” (Art. 23(f) of the Hague Regulations of 1899 and 1907; Art. 39 of Additional Protocol I; Art. 8(2)(b)(vii) of the Rome Statute of the International Criminal Court). Not all uses of enemy uniforms are prohibited therefore; only “improper” uses. For example, wearing enemy uniforms in order to flee the fighting or escape capture does not run afoul of the law (U.S. Department of Defense Law of War Manual § 5.23.1.4). On the other side of the spectrum, engaging in attacks while wearing the uniform of the enemy is flatly prohibited, as affirmed in the treaty law and numerous military manuals (see here, here and here, for example), and is a war crime under the Rome Statute.
The crime wasn’t the payment, it was the falsifying business records. And based solely on the information in this thread, the final signature for those false records did happen while he was in office in 2017.
Just because it happened when he was in office does not make it an official act, but thats their argument