Does Barren Glory require its trigger condition to be satisfied when the ability resolves?
The win with Barren Glory was in fact a bug. Barren Glory's ability has an "intervening 'if' clause", which is described in rule 603.4:


  A triggered ability may read “When/Whenever/At [trigger event], if [condition], [effect].” When the trigger event occurs, the ability checks whether the stated condition is true. The ability triggers only if it is; otherwise it does nothing. If the ability triggers, it checks the stated condition again as it resolves. If the condition isn’t true at that time, the ability is removed from the stack and does nothing. Note that this mirrors the check for legal targets. This rule is referred to as the “intervening ‘if’ clause” rule. (The word “if” has only its normal English meaning anywhere else in the text of a card; this rule only applies to an “if” that immediately follows a trigger condition.)


This means that you have to have an empty hand and no other permanents both at the time that the ability triggers, and at the time that it starts to resolve. In the game in question, the player with Barren Glory had a card in their hand when the ability started to resolve, so they should not have won the game.