A word of caution here!
During the Walsh trial in 1954, FW Franz never said that he "could" not translate a bible verse, he said that he "would" not do so. We are talking about two different verbs - could and would.
Furthermore, when you read the context of what led up to those remarks, Franz was probably within his rights to do (and say) what he did. What was on trial there was NOT his abilities to translate the Bible. That had Fanny Adams to do with what was on the line that day. This trial was about whether JWs were a "church", whether their rank and file qualified as "ministers", and from that, whether this then should exempt their "ministers" from Military Service. Franz's knowledge of Hebrew was a red herring that some smart-@$$ of a lawyer was attempting to introduce.
PS: In case anybody was wondering, I am no fan of the late Crazy Fred!