User blog comment:Blacktitan1031/could have capture the female titan sooner?/@comment-7418318-20130927100025

They had no way of knowing how fast the fem Titan could regenerate or whether she could pull off a third transformation after they cut her out.

With Mikasa almost being killed and Levi being hurt when saving her, I think it was the right decision with the information Levi had available in regards to capture.

Though in his place I would have let Mikasa kill the female Titan.