You don't need a villain. You need a pattern and a reason.
If two teams are actually evenly matched, you'd expect about 50%. The actual rate is higher, and it's highest in the rounds with the most TV money.
Drop in minor-penalty rate in the third period of one-goal playoff games versus the first period. The rink doesn't get cleaner late — the whistles get quieter.
The trailing team in a close third period gets more power plays than the leading team. "Letting them play" works in one direction.
Estimated difference in ticket sales, sponsorships, and TV revenue between a sweep and a seven-game Final — before you count betting. The Final is the most valuable night of TV the league has all year.
Three of the four came in the modern television era. One of them — the 2014 Kings — won the Cup. Improbable comebacks are exactly the inventory the league needs more of.
Refs are evaluated, assigned, and disciplined by the same league office whose revenue depends on their decisions. There is no equivalent of MLB's independent integrity unit or the NFL's external officiating reviewer.
A note on methodology: penalty-rate splits are aggregated from NHL play-by-play data. Revenue estimates draw on Forbes, Sportico, and reported broadcast valuations. Series-length figures are computed directly from Hockey-Reference's playoff archive. All numbers are rounded for presentation; individual cells link to underlying sources where applicable.