If I understand correctly, you want to identify when a form is being loaded immediately following a save in client script.
You can't do this using the form type defined in the execution context alone, but you can do it using a custom attribute. I would recommend a Yes/No optionset attribute, for example, call it "WasJustSaved".
In OnLoad, you check if "WasJustSaved" = Yes and execute your logic.
At the end of Onload, set it to No if it's Yes. Do this via a service call so as not to trigger the OnSave logic.
In the OnSave, set "WasJustSaved" to Yes.
This solution isn't perfect. If multiple users are working with the record at the same time, it could get confused. And you'll probably have to change the logic if you upgrade to 2013 or the autosave will trigger it.