Can't delete copied Time Machine files
I went through this just last week.  Time Machine backups have ACL permissions set.  There are a few ways to see these.  The first is ls -e.  This is from my TimeMachine .bash_profile

ls -le .bash_profile  
-rw-r--r--@ 5 gregcain  staff  6508 Mar 21 13:57 .bash_profile  
 0: group:everyone deny write,delete,append,writeattr,writeextattr,chown  


and this is for my normal one

ls -le .bash_profile  
-rw-r--r--  1 gregcain  staff  6748 Mar 29 13:08 .bash_profile  


If you want to modify these settings, you'll need chmod:

chmod -N .bash_profile