I'm sure you can use an emergency call up if it's for an injured player. Have been able to in the past.
Good point and emergency callups are extremely easy to complete since they are already practicing with the team.
I really wish they'd clarify the rules here though (or if they have someone could point me to it, I couldn't find it in a google search other than articles that sometimes contradicted each other). The way the rule reads is that it only permits 4 recalls from another league. Does Taxi count as another league.
The point of the rule was to prevent teams from calling up the entire farm for the last few games negatively impacting the AHL team and negatively impacting the marketability of the NHL game. Back and forth on the taxi doesn't have the same impact in my opinion.
It would also be beneficial to get clarification because Bouchard wasn't assinged to Bakersfield at the deadline, so strict reading of the rule is that he can't be sent down, but if for the purposes of the recall rule Taxi=AHL then it's fine.