Power Co. engineers, or planers as they are called here, get their “specs” from the engineered drawings done by a registered engineer. They look at what the actual demand will be, not the connected load, and size accordingly. They always tend to size to the low end to reduce cost. If you added a considerable amount of load to this facility you could have very well exceeded the capacity of the utilities feeder without exceeding the actual service equipment rating. Hard to tell without more info.