Abraham thought for a moment about "playing hero." If Hellboy were here he would have staked the woman without any thought of consequence. With Hellboy it was simple. He only gave the supernatural the benefit of the doubt for long enough. If they were going to go right out and say what they would do there would be no hesitation.
But, with Abe, hesitation abounded. Hellboy didn't sense their emotions, he didn't consider his location. He was reckless. That's what made him so good. And what made Abe so good was that he thought about things...a lot.
This person, dead or not, was someone The City had brought in. That meant something. He had no idea how things worked here with those brought in. This society was foreign to him. 'Right' and 'wrong' were...flexible in this new environment. He had no idea who this vampire was attached to or, if her 'Maker' did come back, if he wanted that vindictive personality to deal with while being so new here.
He must have seemed, for a few seconds, as if he were daydreaming for a while. But when he refocused he looked at her and decided that maybe it was better to let her be. It felt twisted in his gut to think that, but he couldn't judge the consequences of killing her.
"What do you think of this coat?" he said abruptly turning his attention fully away from her to stare at the long tan coat he was considering purchasing in the dressing window.