Is there a way to know if a script was triggered from the Netsuite UI or a Map/Reduce script? I have a User Event script attached to a record that should not be triggered a Map/Reduce script saving records of that type.

you may check deployment logs

Is there a way for the script itself to know what triggered it? I want to prevent it from executing certain code if it was triggered by the Map/Reduce script

you could isolate it by the execution context. using runtime module, you may use executionContext in there and then just log the execution context on the script so you could isolate the issue

I'll give that a try, thanks!

You could use context execution to see whats triggering and executing