How to fix drywall bowing from exterior, blown in insulation?
Did they blow in dry fiber glass, cellulose, or wet foam. Years ago my brother- in- law got into the foam insulation business and foamed some houses. The wet foam loosened the glue and the drywall bowed. His insurance paid to have the drywall replaced on every wall effected. After that event he would never take another insulation job where that same builder built the house since they used glue and only a few screws to hold the dry wall in place. My guess would be that the insulation contractor is " on the hook" for the bowed walls. I would call him and show him the problem. Let him decide what to do.