Recently, I discovered a bug that can be bypassed by playing through the situation that triggers it without a mod (i.e., this bug doesn't occur without HD).
I won't describe the conditions for the bug to occur in general just yet, but at the very least, on the save files of one map (an example save file is attached), this bug occurs consistently: simply enter a cell with an event while simultaneously engaging in combat with a neutral unit on an adjacent cell, and then escape from that battle.
As a result, the entire puzzle map is revealed, and instead of the hero who fled, a hero with eight expert secondary skills, a relic artifact, and five mega-dragons appears in the tavern.
WHO'S CHEATING??? IT'S DOING IT BY ITSELF!!!