I am an RA (soon to be PhD student). I work in a fairly multidisciplinary research group where each of us has an extremely different academic background. My specialization is in signal processing, so I have been put on a project that requires me to implement some complex algorithms.
We just had a postdoc join us and he has zero experience in this area. At the third lab meeting where he has been present (and I have been giving updates on my work at each one), he stopped me and said, “actually, this is how you can solve the problem…” He went on to demonstrate, in detail, his complete lack of understanding on the topic, going as far as to get two extremely fundamental concepts entirely and laughably wrong. At first, I tried to jump in to comment, but no one could get a word in, so I eventually let him ramble on. When he stopped, I politely pointed out that his description had been completely off base because it was based upon his incorrect understanding of really fundamental principles.
So infuriating. I was kind about it. But in the end, he looked ridiculous.