@Blitz Boom
Going back to the scene of the crime, Pop would see the alley empty, the three henchponies already left while leaving no evidence of a struggle ever occurring. However, Pop knew the changeling is in the green trash box, the lid closed properly. She may take a peek if she wanted to check if she's alright. It's up to her to decide: open the cover or leave the premises immediately to avoid involvement.
Opening the lid is to reveal the current condition of the changeling, however, staying for too has consequences.
On the other hoof, leaving immediately will arouse less suspicion, but even this choice still had unpleasant outcomes
...
Speaking of arousing suspicion, Tepe was taken back of Sorrow's sudden concern, though he didn't think much of that. But there was something odd of her dialogue...as if she knew what he feels. It was just weird. While he and Tepe agree to Sorrow's idea, Windy had another inkling.
Checking the door leading out the 'house', it only made a click, however, did budge “Mmm, this door needs fixing for its lock" she said to herself, voicing her thoughts. She tried to turn the knob but was still unsuccessful. After three more attempts, the door finally gave out, opening with a loud creak.
Turning to Sorrow, Windy finally spoke about her move — which can only be described as 'genius'.
“I'm thinking of staying here,” she told Sorrow.
...
Circumstances were getting worse. It's not surprising for Cali to not take it easy of Light's deadly move, but indiscriminately attacking every single pony in the room is not what Luna expected, the latter laying on top of Blue, whom she saved from being struck by one of the magical beams by throwing herself at her. Worse, Light had jumped out of the window, literally. It was an extremely dumb move done by instinct. She screamed out to him, but was already too late; Blue screams, ringing inside Luna's ears for a few moments before recovering. She quickly gallops to the window, peaking down at where Light fell. Meanwhile, a hysterical Blue lay her forehooves over hers, and wings concealing her face; whimpering and sitting on the floor.
Luna wouldn't give Light the chance to hear the creature speak as she would call out to him from behind, having left the hospital in a haste “Light, is that you!?”