The goblin queen is frozen and she uses green mana, turnip is cast which makes green gems, fills gobtruffle, the chink sound is heard, and she gets her mana filled, then they get an extra turn. She is still frozen. Seems like that should have ended their turn
This has been happening for several months, several times a day with looping teams that are frozen.
Steps to make it happen again
_Load up a team that can freeze other team, fight a team that makes gems and gets extra turns.
All the game requires is for (at least) one Extra Turn to not get nullified by a mechanic like Frozen for that side to keep the turn. In your linked video, the 4+ match of Green can’t generate an Extra Turn because the Goblin Queen is frozen.
But Norbert’s Turnip having the Quick trait (at +9) is a check independent of the Goblin Queen. And since that check succeeded, your opponent keeps the turn regardless of what happens in the aftermath of casting that particular spell/weapon.
It’s as Potemkinz and Kezef have said this isn’t a bug. If one Troop with Quick Trait has the status effect of being Frozen, but another Troop in that team also has the Quick Trait the extra turn will be granted as each Troop Ability and Trait is independent from one another.