I was able to catch it in the picture [attached]... When attempting to place a torch against glass it will attempt to auto-attach to the nearest "attachable" surface which causes the no texture mesh to be visible momentarily.
(Used the search and didn't find anything... sorry if this has already been reported, I tried to make sure before posting).
Ahh yes, i hadnt gotten around to reporting this.
I found if i sit in creative in a very large open area an place torches on the ground while holding the place button down an walking it will also do this as well as walking along a wall placing torches using same method.