If we are trying to repair a piece of equipment and keep testing it to find out what is wrong, we have a lot of trouble if more than one thing is broken. Once we find one fault, we may be tempted to attribute all the symptoms to it and miss the other fault, so we fix just the problem we know about, and the result is that the equipment still does not work.
I've experienced this many times when I've been digging through logs and find something that is off. It's easy to attribute a bigger impact to the finding than may really be warranted.
