I never thought it was a template issue. I understand the problem and it will take some work for us to improve our logic in one of a few possible ways to either detect that you're on the edit page or detect if the tag is in a textbox area. Either way will take some work on our end, and it won't be something we'll have a solution for tomorrow.
Ultimately, we've supported Easy-Tags for more than 4 years, and this is the first time we've heard of the issue. The overwhelming majority of Joomla users edit articles from the backend, which is what we cater too. We will look into this, but until then, we'd recommend using the back-end editor or use alternative ways to add the {SCOpenGraph ... } tags to the page, like a custom HTML module on those pages.
I hope that helps,
Alex