I’m a little late to the party here but wanted to share this article I’ve just written that happens to have a workaround for adding the response to both the Google Form and Google Sheets: 

Hope that helps! :)

Thanks mate

I've made the Zap but it only seems to add a new row in the original spread sheet, not create a response in Forms

Any tips?

Hi @Dshirt 

Yes, that’s totally doable. Here’s how the workflow will look:

• Trigger: New Row added in Google sheet.
• Action: Create Response in Google form.