Just a friendly reminder, we all signed the honor code and should be courteous. Language like "serious ?" and "I am not American and I know" implies scorn that someone (you don't specify who) made a stupid mistake somewhere (you don't specify where).
It's probably better to initially assume, if something doesn't make sense, that you have misunderstood something. For instance in this case it turns out, all the presidents are accounted for, you just didn't understand how connections are counted (see below).
If in fact you had found there was a real mistake, that's great. We should all be happy to jump in together, as fellow volunteers, and fix it.