They did not shoot holes in the roof to cause it to collapse. Three panels had collapsed due to heavy snow and wind. They eventually shot holes with a shotgun slug in two additional panels to prevent uncontrolled collapse and protect workers who would be on the roof - per AI overview.
interesting read here. some of it from perspective of the maintenance guys working that night that tried to keep it from coming down.
https://www.vikings.com/news/longform/metrodome-roof-collapse-2010-aftermath
I was in the dome when it almost came down during a Twins game in April 1986. Thunderstorm with 80 mph winds tore a hole over RF. The wind gust pushed RF side of roof in and the opposite side bulged out. Water came pouring in and sensors on the bulging side went off thinking that the roof was over-inflated, dropping the air pressure making it even worse. The roof began to deflate and sag and the lights and speaker panels started swaying wildly. It was crazy and very scary. We were in LF bleachers near he field. People in that section went to to top and stopped to watch once they were safely under the overhang from the upper deck, blocking the exits. We couldn't get out and were stuck there until they got it under control. Some people jumped onto the field and ran into the dugouts. They played after a delay but we got the hell out of there.
I can still hear Bob Casey on the PA. - Don't worry fans, even if the roof comes down it can't touch the seats so you are safe. A minute later - EVACUATE THE UPPER DECK! EVACUATE THE UPPER DECK!