A persuasive and subtle case but, despite that, I think it's still a red. Just...
... but that's because I like rules/changes to rules that favour attacking players, which colour my assessments of incidents.
The big difference is that the keeper was near the half way line, and there were no defenders in front of Bale. That makes that situation considerably less rare than rocking horse shit. I think it was clearly a goal scoring opportunity, which is something different from a nailed-on goal.