Allstate Insurance Co.’s delays in adjusting claims in Louisiana after hurricanes Katrina and Rita were justified in light of "severe problems, impediments, roadblocks and hindrances’’ created by the storms, state insurance regulators said in a report issued Friday. The Louisiana Department of Insurance examined a sample of 120 paid claims and 120 open claims by Allstate after the 2005 hurricanes and found nine instances of delayed payments. But those delays were not "arbitrary’’ or "capricious,’’ the department concluded.