The matter of concern is public record. It shows that the Canadian framework is not sufficiently robust to lay out clear rules as to what is and is not acceptable, both while in office and when out of office.
Rather than looking back, the valuable work the committee can do is to make sure that we lay out much clearer rules and lay out clear penalties for violating those rules, whether they're being violated by Canadians, by foreigners or by accredited diplomats in Canada.