תרגום - לטינית-אנגלית - ipsa rem comfirmavit hoc dictum!

Hm, sth wrong is with Latin here.

Obviously should be "ipsa res comfirmavit hoc dictum!

The translation is ok.

The second possibility ""ipsam rem comfirmavit hoc dictum!

but then, the translation would change:
"this word/expression consolidated the same thing"

I think it is more possible and we should ask the requester to check the source.

Yes indeed ! "ipsa rem" is wrong. I believed it was in nominative case. "ipsa res" (nom./voc. case) and "ipsam rem" (acc. case) can match.

Maybe there is an inversion between "ipsa" and "res".
For example "Res ipsa loquitur" => "the thing itself speaks" or "the thing speaks for itself", well-known expression in law.

I don't know what inversion you mean. Do you mean we have here "ipsa res", and not "res ipsa"? The opposite order is possible even if it is not stricte Latin order.

If it is in nominative it is a subject. If it was in accusative it would be an object. That's all.

The point is that "hoc dictum" is neutrum, so it could be as well the subject as the object. Everyting depends on "res ipsa" or "rem ipsam".
So, if you say it is nominative, the translation is fine.