One periodontist said he could not place bone graft material after extraction since bucal wall broke. New perio. Said he could have. What gives here?

It is possible. and usually combined with additional augmentation utilizing a bone substitute material and a collagen membrane. See a "new perio."
Not sure... There are different types of bone grafting material that can be used to augment a ridge like yours. Used together with biological membranes the procedure is quite successful. Not sure why you first periodontist felt this would not work in your situation. If your new periodontist feels they can remedy the defect, then allow them to do so.