It is impossible for every person to follow every protocol perfectly every time. The only thing you can be certain of is that at some point there will be a failure at a protocol weak point or that there will be a breach of protocol. These protocols do not eliminate the risk of infection, they reduce it.
This is a fundamental precept of risk analysis. If they haven’t taken this into account, they are idiots.
You might not make the mistake, but someone will. And after 30+ years in the healthcare business, it seems that “the” mistake is made by someone who is certain they wouldn’t make a mistake. Or a piece of equipment or protective gear fails.
One of the things I’ve had to plan on when designing class 3 medical devices is that someone is going to make a mistake. You design against it, but even in the best case the mitigation can only reach the probability of occurrence is “indistinguishable from zero.” I.e. it is still considered a risk that can – and usually ends up – happening.
Never underestimate the ability of people to screw up the best laid plan.