All of the tingles concentrated to her hand and wrist slowly dissipating up her arm just before she hit him. Makoto's open palm made contact with Mimic. A jolt of ... something happened right during the strike, pushing her back away from her teacher.  It hurt a bit but what was the biggest shock to her was the audible crack of ... lightning? Her ears must have fooled her in the heat of the moment, regardless she let out a cry of surprise. In all reality though, she gave Mimic one hell of a static shock. It would have caused some major nerve jumbling and burns from being that close. 

Makoto quickly tried to survey hr arm, thinking she broke a part of it on him, only to look up and see that she had burned through his shirt and into his skin where she hit him. Dread flooded her. She hurt her teacher? She hurt her teacher! She wanted to rush to his aid an apologize. If the circumstances were different she would have, her teammates continuing to fight was what kept her from doing so. She tried to move around Mimic, not staying in the same place too long. She was all the more unsure of her powers but tried to hold onto that trust and acceptance of herself, to those tingles in her arm.