In Interstellar movie I almost had a syncope when Dr. Romilly explains how a wormhole works to Cooper as if he were a 5-year-old child and not a former NASA astronaut.
I have been in the room where seasoned doctors are talking to junior doctors like this, I think its normal. Sometimes people that are really smart can dumb down their subject of expertise in a way that an outsider might seem like they are talking down to someone
i think it's partly because it's often very easy for experts to overestimate what non-experts know, even people with some knowledge in the field (relevant xkcd as usual), so it's probably easier to just dumb it down as much as you possibly can. That way you're sure most people can actually understand.