Git pre-commit hook that checks for open application

I am using git to manage a project that has a few binary files that need to be closed before being committed. So I need a git hook, that checks to see if the application that has these files open is running.

Here is the script I am using

#!/usr/bin/env osascript

tell application "System Events"
    set apps to the name of every process whose background only is false
end tell

if "Some App" is in apps then
    error "Some App is running. Can't commit until Some App is quit" number 5
end if

But I am getting this error when I commit or execute the pre-commit. Even when "Some App" is not running.

.git/hooks/pre-commit:50:106: execution error: An error of type -10810 has occurred. (-10810)

Permissions on the file are

-rwxr-xr-x@ 1 toddgeist  staff   263 Dec  7 07:33 pre-commit