Julio is very right. Its not about the S1, S2, S3 or C1 exam per se that there is a 7 day wait if one fails one of them. VATUSA staff knows that no one is 100% perfect, hence allows for 20% of the questions to be marked incorrectly before one fails, meaning 5/25 of the rating exam questions are allowed to be marked wrong.
These questions represent only a minor fraction of the required knowledge the controller needs to posses to earn the rank sought. And yes the open book thing allows all controllers to look up answers to the questions, may it be in the VATUSA Training Resource Center, the 7110.65 or other applicable documentation.
This is not a Half-Life game that you can finish and be an expert in a week or two. Everyone is always learning, regardless of seniority, rank or staff position. Thats what we need to respect and value.