I take it you don't run many investigative games. I do. The notion of having PCs miss important clues died sometime in the 1980s when Call of Cthulhu referees would stop games when PCs missed the single roll that would reveal the single clue the PCs needed to continue playing the game. Since then it's been common practice for important clues to simply be found. No roll required. Just found. The important thing to remember is a single clue isn't the solution to the mystery. The players can still misinterpret that clue and the PCs still need to correctly interpret most of the clues to solve the mystery, so nothing is lost by simply giving the players the important clues. They still have to solve the mystery themselves. The vast majority of the time the PCs will be trained professionals or skilled amateurs, but, importantly, the players will not be. The players will misinterpret the clues, guaranteed. The players will go in the wrong direction, guaranteed. The players will Pepe Silvia their way into the wildest and most absurd conclusions, guaranteed. You don't need to intentionally introduce false information (aka red herrings) into the mix. You will get the same result by simply playing a game with an investigative element.