You Don’t Gotta Tell Me
We’re not going to pretend that we know even the slightest bit about software engineering. However, if your new hires are courageous/foolish enough to go up to the project manager, someone who had been with the company from practically the beginning, you should probably have more to say to her than what she already knows.
It’s possible that these guys were trying to impress her with their knowledge of software engineering. That’s nice and all, but c’mon! There’s no way you didn’t know about her credentials before you joined the team! And even if you didn’t, maybe ask around before you make yourself look like a buffoon.