SacrificeSourceTriggeredAbility not respecting controller change

Title is informed speculation.

Observed behavior:
Player A cast [[Slave of Bolas]] to gain control of Player B's [[Daemogoth Woe-Eater]]. When Player A sacrificed Daemogoth Woe-Eater to the delayed trigger of Slave of Bolas, Player A was forced to discard rather than Player B. Expected behavior is that Player B should be forced to discard, not Player A.

Also observed:
Player A cast Slave of Bolas to gain control of Player B's [[Colfenor, the Last Yew]]. When Player A sacrificed Colfenor to the delayed trigger of Slave of Bolas, Player A did get to return a creature card from their graveyard as expected.

Honestly not sure where in the engine this would need to be fixed.

Reproduce the two Slave of Bolas scenarios, then search the Java source for Slave of Bolas, Daemogoth Woe-Eater, Colfenor, and SacrificeSourceTriggeredAbility. Trace how the delayed sacrifice trigger determines the controller, and verify that the affected player discards while Colfenor's graveyard return behavior remains correct.

Written by the indexing model from the issue text.