Nice as it's been to see Stephanie growing into the role of Batgirl, I think she channeled Batman too much with the Grey Ghost. Like I said in my review of Batgirl #21, Clancy appears to be setting his own War Games-style foul-up into motion.
The situations aren't completely similar, but in both cases a more experienced hero is trying to convince someone else they aren't cut out for the work because they don't have the right mindset. In both cases, they state their case bluntly/harshly, and in both cases the less experienced hero has settled on ill-advised course of action designed to prove their worth, which will instead end up proving the point.
Maybe. Clancy's story hasn't finished yet. Still, Stephanie's problem with him is his only concern is for her. The inhabitants of Gotham mean nothing to him. His own safety means nothing, and even stopping the bad guy takes a back seat to making sure Batgirl's OK. Now he's provided the Reapers with another thing they need for their master plan, which is probably bad news for Gotham City. He did so on the condition that they leave Batgirl alone. Basically proving Steph's point.
I guess that's why Batgirl tried to dissuade Clancy gently at first, she recognizes some of her old self in him. That having failed, she opted for harsher methods, even though that never worked with her.
Admittedly, I don't know how she could have handled it differently, but there has to be some way to either convince Clancy to hang up the costume, or get him some training and a better mindset. He's obviously clever, and when he sets his mind on a goal he'll come at it from all different angles to try and succeed. He just needs to broaden the scope of his protectiveness. Hopefully it doesn't take a citywide catastrophe or a near-death torture experience to bring about that change in him. Because we sure don't need another load of crap like War Games.