Pilote's playoff PK usage was even lower than his regular season usage.
Not sure if you have seen these discussion on the history board recently. The recent NHL data release shows that one major reason for the 60s Blackhawks' playoff failures is power play goals against. They allowed 71 power play goals in 67 playoff games from 1960 to the 1967 playoffs. That's about 1.5 times the rate that Detroit, Montreal, and Toronto allowed power play goals against. While power play opportunities aren't reported, the penalty totals are pretty equal across teams and there is no reason to think the Hawks were shorthanded more. So everyone involved in the 60s Hawks penalty kill should get docked for this.
NHL.com - Stats
Pilote was only on the ice for 23 of those 71 power play goals (32%). You can see the rest of the players at the link below.
NHL.com - Stats
You could argue Pilote shouldn't get much blame for this because he wasn't involved very much. But you also have to ask -- why did the coach not use Pilote in a larger role as the team kept losing games and series because of their penalty kill? You could ask the same about Mikita and Hull -- sure, they were relied on to score, but Detroit was using Gordie Howe and Alex Delvecchio in all situations too and with better PK results in the playoffs.
Edit: I checked the numbers and I was wrong about Delvecchio. Only 7% playoff PK usage. Norm Ullman was at 34%, Howe at 22%, Mikita at 14%, and Hull at 13%. So not a huge difference in the individual numbers, but the key difference is that Chicago's PK unit was consistently bad in the playoffs after their Cup win in 1961. Maybe their big mistake was getting rid of PK specialist Earl Balfour.