Hey, it's a pithy one-liner (two-worder) -- and like any such chestnut is going to be wrong a lot of the time.

Even so, learning from someone else's mistakes is "cheaper" than making mistakes yourself. The further you can get by avoiding mistakes others have made so you can get to your own personal mistakes, the better.

I'd say "err vicariously" gets better the more you think about it, rather than needing to be nitpicked.