One time I had this experience in reverse; I was investigating a problem and found a forum post about it from an ex coworker with a recognizable username. (Unfortunately he hadn’t found a solution, either.)
I’ve run into that where code was twisted in knots, so I went with an intuitive approach, just to run into an error. See ex employee from before my time’s post. Revert, add comment detailing why, with link to post.
Edit - Also, another coworker reviewing PR with notes commenting “oh yeah, I wasted a day on that too. Good call on the comment and link”