I've manually copied files from my time machine backup drive and now I cannot delete them from my computer
I've sorted it out. First, you need to look at the ACLs that got copied along with the files.

ls -le /path/to/dir


Once you've done that you can see that everything had this:

0: group:everyone deny write,delete,append,writeattr,writeextattr,chown


So, what I did was add a new ACL policy to the directory by doing this: 

chmod -R +a "admin allow read,readattr,readextattr,readsecurity" dir 


Followed by:

sudo rm -rf dir