Suggestion: make this feature an option that can be enabled / disabled. I agree with your points on why there would be harm done to the user interface if this sort of icon is present on every line.

Sounds good; I hope your idea will fix it! Can you post here when you post the update with the fix? I want to make sure I make a note of the update and look for the problem recurring.

I am using:

Windows 7; latest Chrome 28.0.1500.72 m

It has been occurring for the past several updates of Chrome as well.

Also, they often have a "still loading" spinning circle in TO next to them, for a long period of time.

Wish I could reproduce this on demand, but I don't know how. I'd have to have a screencast running for a long time, sharing all kinds of things on my screen that I don't want to share! 

To answer your question though: the vast majority of time this occurs when I do a search by typing in the address bar. Most of my phantom tabs end up being Google search tabs. Most, but not all. 

Any luck with your issue Jonathon? If you're experiencing this with every tab, perhaps that's the root of the problem. I still have this issue on a regular basis.

PS: I duplicated the tab from Chrome's interface. The new window shows up, but without a Google icon in TO. Strange...

This is a very helpful feature. I will start using it regularly! I found however that it doesn't work when restoring groups. Can you extend the functionality to groups?