other person who froze time _ I know who it was....
it was his ex-girlfriend. he was still so in love with her, that time would not stop for her when he stopped it.
when he finally kisses the new interest at the end and freezes time and she is not affected, it shows that his love is transferred to her now.
the other at the soccer game was his ex-girlfriend following him around, as she realized when it first did not affect her and would go on for days and one time for a week, she started exploring what was going on and went to his house to see what was going on with him - if he was also frozen. he wasn't, so she followed him in her off time and watched what he was up to. she knew he worked at the grocery store late night and was probably there watching him.
that explains why she would be at the soccer game - she was simply following him waiting for another event to happen.
"I need a six-demon bag."