I guess you could rub it off with denatured or rubbing alcohol, but this would take longer than scraping it. It seems kind of odd to me though that you would even have a conversation like this with the painter. It's his fault the paint is on there....and he's saying he won't clean it because he may scratch the glass?

Scraping with the razor blade is the best way and you can reduce the risk of scratching the glass by using even pressure on the blade and changing them often. Also, it helps to spray some glass cleaner on the glass which acts sort of like a lubricant for the razor blade. Scraping dry glass would be more likely to scratch it.

Thanks paintguy. The panter said he couldnt guarrantee that he wouldnt nick the window. I was hoping there was someting to spray on it that would easily remove it. I will have him try the denatured alcohol first.