I don't think the commenter meant to literally look stuff up during an interview. A good interview is more of a conversation than an exam. During that conversation it would be perfectly normal, even expected, for the interviewee (or even interviewer!) to say something like "I would need to check the specifics in the documentation" or "I don't know what X is, but let's assume it's Y".

Nobody can possibly hold all the knowledge they'll need in their head at once. A fundamentally important part of any skilled job is being able to adapt, improvise and learn on the job. This is what is being tested, not what you know/don't know.