I created a local Git repo on my laptop and then pushed the source to Heroku creating a remote branch. After a few days of commits and pushes, I need to rollback to an earlier commit. Here's what I did.

cd <app root>
git checkout 35fbd894eef3e114c814cc3c7ac7bb50b28f6b73 

Someone told me that doing the checkout created a new working tree(?) and not the branch itself, so when I pushed the rollback changes to Heroku, it said everything is up to date and nothing was pushed. How do I fix this situation? Thanks for your help in advance.