Being open worked in your case because, as an interviewer, you answered in an open, honest way. The article is about uncovering the truth when the interviewers are being cagey.

If there isn't reason to suspect that the truth is being glossed over, being direct is a simpler, clearer path. But if things sound too good to be true, you may need to figure out how to get more information, like open-ended questions. I'd follow that up with probing questions to dig deeper towards anything that sets off your spider-senses (but ask in a nice way and continue to present a friendly vibe).

I think this is very similar to being on the interviewing side. People talk about impressive projects they worked on, but that could mean they contributed to a small part of the project or they had real responsibility for the project and its execution. Everyone is putting their best foot forward so you have to ask follow-up questions and dig to uncover the truth.