As with any programming, the more time you spend writing execution modules, the more likely you are to encounter issues. Let's take a moment to talk about how to troubleshoot and debug your code.
The salt-call command has always been a valuable tool for testing and troubleshooting code. Without it, you would need to restart the salt-minion service each time you wanted to test new code; believe me, that gets old fast.
Because salt-call doesn't start up a service, it will always run the latest copy of the Salt code. It does do most of the things that the salt-minion service does: it loads grains, connects to the Master (unless told not to) to obtain pillar data, goes through the loader process to decide which modules to load, and then performs the requested command. Pretty much the only thing it doesn't do is keep running.
Using salt-call to issue a command is also the same as using the salt command, except that a target is not required (because...