Sorry. I used window and window glass interchangably in the context of cars because it's understood that the frame of a car window is not detachable since they are a part of the door. So I loosely interchange them. By the way, literally pulling out a window without first removing the bolts that fix the window onto the window regulator will break the glass, as far as I know. I might have misunderstood your question entirely. Maybe we're not on the same page here.
Please correct me if I'm wrong.
(Edit: May be irrelevant
Using suction cups or hands to push down a window forcefully but gradually usually will not break the glass. However, the cable will tangle or break as a result and the regulator will have to be replaced. The most frustrating thing is some regulators are sold together with the motor so
you might need to buy pay for the price of a motor though it's still intact. :(
)