A click on a column heading will change the sort field, and you can reverse the sort order with the small triangle. So, for example, you can sort the list by Name and see all updates to any given app, or sort by Date to see what's happened chronologically. Viewing my log chronologically, I see a total of 15 updates since May 1st, all but one of them successful - the first try at IE 5.1.1 failed for some reason.
I'd been browsing the /Library/Receipts folder to find this information, and all this time it was a simple button-press away. Sometimes, it seems I overlook the obvious in search of the obscure! Thanks, Jim!

