It may be the case that whoever took it threw it out once they saw that there was no money included, or that your husband just dropped it. A bank account or credit card could not be obtained without a bank statement anyway so it is not a major worry. Just in case, keep a close eye on any bank statements you are due to receive and store them safely.
Having notified the Gardaí in advance, you should be in a better position to resolve any identity theft issues, unlikely though they are.