A start was good enough for her - at least, for the time being. She realized that she was better off than she had been, and at least now she could be prepared if the unexpected happened. Whether she fully trusted Luther or not was something still undecided, but being a police officer was a strike in his favor character-wise.
Hannah managed to catch the water bottle, but barely - she hadn't been paying all that much attention. "File a police report, of course - the sooner the better." Even if she hadn't done that in her own case, it was common sense.