By law, a visa number should not be "used" by the USCIS until an applicant's adjustment of status application has been granted.
8 USCA 1255(j)(3). See also 8 USCA 1255(b).
IF the USCIS was requesting visa numbers in advance of approving cases, then visa numbers were not really exhausted on July 2nd. And if that is the case, we think they violated the law in a frantic attempt to use up all the visa numbers by July.