HomeschoolDad:
The Precious Blood didn’t get consecrated.
I don’t see how you could know that.
Because the Church prescribes very specific words of consecration for the Precious Blood in the Latin Rite (as well as many other rites). If a rite has organically developed without such words, as in the Assyrian Church of the East (I think you must be referring to the Liturgy of Addai and Mari), so be it, that too was the work of the Holy Spirit through the ages, but the Church the right, the prerogative, and even the obligation to specify what has to take place to consecrate the elements, and what cannot be done without. The Church in her wisdom, guided by the Holy Spirit, determined that the Assyrian liturgy was indeed a true Mass with a true consecration, even though that consecration cannot be “pinned down” to a specific moment, as it is the Latin Rite. For lack of a better way to put it, Eastern Christian spirituality is not so concerned with such questions as
“precisely when does such-and-such happen?”, rather, it is more concerned with
“how things end up”. But the Latin Rite is more precisely circumscribed than that, and cares equally for both.
No doubt everyone at the Mass, sincerely disposed and “gathered in His name”, received divine grace, but fact is, they did not receive the Precious Blood. Assuming no one “caught it” at the time (and I find it difficult to believe that nobody would have noticed), needless to say, there would be no subjective moral fault.
What’s done is done. The priest needs to be made aware of his inadvertent error, and if his priestly formation is soundly orthodox, he will know that he needs to “resume this Mass” privately, so that a true sacrifice will have been confected and completed. (Not sure what he would do about receiving a host, I assume he could just retrieve a previously consecrated one from the ciborium.)