Ryu is hard to get on the same page with as a catcher and he likes to get his pitch quick. Kirk has more experience with him than Collins who may not have caught him yet even in bullpens. The bigger question would be why Springer isn't the DH instead of Collins.
It's a mistake, but in that situation and with the current score it's not really all that terrible. Getting a runner into scoring position there is worth taking some chances. The Chapman mistake last night was far worse.