There is no good wording that could be utilized in such a memo. If it says there was pressure, then Comey broke the law by not reporting it when it happened. If it says there was no pressure, then it reveals Comey as having nakedly attempted to harm Trump with a lie.
Best option: refuse to produce the memo.
Is this memo something that could be subpoenaed?
Yes, it’s strategic from the anti-Trump standpoint: Comey isn’t incriminated and the ambiguous implications hang around Trump to continue their destructive narrative.