While I can't comment on this situation in particular (a room of computer science researchers who couldn't understand basic notation), I can offer an anecdote a

While I can't comment on this situation in particular (a room of computer science researchers who couldn't understand basic notation), I can offer an anecdote about the lack of mathematical knowledge in industry. Yesterday one of my coworkers submitted some code to perform an upsert to code review. His logic for calculating the diff set was extremely complicated, and subtly wrong, filled with comments. To me the idea was incredibly simple, because I only needed to think of the upserts in terms of set notation. So in review, I wrote the set notation implementation of the upsert, and then offered code to implement the idea. My coworker was taken aback at how simple this set based implementation was, despite it being very basic set mathematics. While this was just an anecdote, I find that a lack of basic mathematical fluency peppers codebases with unnecessary complexity and myriads of edge cases that could easily be tamed with a slight application of mathematics.