No, it doesn't "cancel out", but courts (not law) absolutely do "both sides" issues.
Rebukes for "winning" sides of a suit are relatively common.
For example, here's a case in Australia where the defence are criticised for over-reliance on AI, where the defendant was still found innocent by reason of insanity. [0] Most of the ruling is criticisms for the "winning" party.
If they notice. Again, a printed version of the contract that is signed has no evidence of the attack. The attack is on getting your legal LLM to hallucinate specific things of what you are signing.
I doubt a judge will look favorable on people saying "but my LLM said it was 1k"... cause they are known to hallucinate.