No it doesn't have to recover 170 GB of data. It has to rollforward, or most likely rollback the active transaction you killed mid-process.

You just happened to do it at a really bad that on that day which caused you to wait.

Seriously do everybody a favor and read both articles I pointed out and set up real maintenance on that server. The log won't grow to 170GB and you'll be able to restore in case of a disaster. Which judging by the SQL knowledge of the admins is likely to happen.