If that picture shows the pipe after you buffed it with scotch brite and it is ''bowed'', in other words warped, then the pipe is damaged IMHO. The weld spots would have to get very hot for them to break - but it could be possible for the metal walls, themselves, to weaken and collapse under thrust and heat if they have been heated enough in the first place via direct flame for a long enough time to weaken them.

Only you know how bad the pipe looked before the touch-up and how warped it is. It's hard for me to tell in the pictures but I'm definitely ''conservative'' when it comes to these types of situations so please take that that for what it is worth. I wonder if your hot tail is a sign of a pin hole leak in the pipe or a crack. Is it a dual walled pipe?