I'm not sure "Person who answered a question didn't actually know the answer" is such a good defense, almost worse than "We didn't understand the license", because the implications of having such people in your company seems way wider then.
Compliance tech company who doesn't know about open-source. Interesting.
That is very much true. Lack of knowledge in a legal context is a very weak defense.
Generally speaking, open source ecosystem knowledge is not something that shows up in job descriptions, interviews, or regular training for non-technical staff in most software companies. Hopefully that will one day be the case but until then there is a high likelihood that misleading statements can be made accidentally.