augh i'm being super slow too, i still need to finish her bio. it's been probably a year or so since she started training so that probably doesn't line up. but maybe they've worked on the same case before? she's sort of a sarcastic hardass out in the field, so she could have thrown her weight around and hit him on accident. she's also a huge flirt, so she could have just said something to him as he walked by in the precinct.