Can it be someone that was super overrated for a short period of time rather than their whole career, like Bill Ranford for the first half of the 90's?
He wins a Cup and a Conn Smythe as a 23YO. Some less than stellar years with the Oilers that followed were supplemented by good looking international appearances for team Canada, which led the hockey media to become convinced that he was a top goalie being held back by a bad Oilers team.
In his last couple of years in Edmonton, anytime it's reported or speculated a team might need a starting goalie, Ranford is always rumored to be the #1 target with a value that should net some kings ransom for the Oilers (IIRC Shanahan AND Joseph from the Blues, a huge package from the Wings that would contain both Primeau AND Osgood, a package with Redden and Muller from the Islanders, a package around Owen Nolan and Thibault from Colorado, something huge from the Flyers, etc. etc.)
I was reading some old articles from around then and stumbled upon some of the Ranford hype:
-An article about how Mike Vernon is the Wings Achilles heel going into the 1995 Finals. The article mentioned something about how Vernon isn't anywhere near the level of the top goalies in the league which it lists as Hasek, Roy, Belfour, Ranford, Felix Potvin, and now Brodeur.
-Another one touched on Ranford's arbitration award given in the '95 offseason, where a 1 year $3M deal made him the 2nd highest paid goalie behind Roy. The article actually makes mention that statistically he was the 40th or 41st best goalie in the NHL the previous season, but then makes sure to point out that it was 100% the rest of the Oilers fault.
I also looked up some articles about his trade to Tampa and was surprised to find the hype train was still alive at that point. He was acquired for a 2nd and 3rd and pitched as a legit #1 goalie to finally replace the perpetually injured Daren Puppa. His tenure as a back up with the Caps the previous year was explained away as simply a couple of Ranford injuries allowing Kolzig to go on a hot streak that lasted the whole season.
Another candidate for overrated for a short period might be Jim Carey.