  If you run ls -al you can see what directories and files have an ACL applied.  A "+" sign indicates and ACL.  You can tell what ACEs are in the ACL by using the special flag on the ls command (ls -le) from the Isilon cluster command line.  The "-e" allows you to see all of the ACEs within an ACL.   To fix this problem, there is a button in the OneFS WebUI under:   Protocols / ACLs / ACL Policies that allows you to "make ACLs created on directories by UNIX chmod" inheritable.    
 UNIX users are getting access denied in response to files and folders that they just created on an Isilon NFS export, how can that be?
UNIX users denied access to files they just created?