They should all fail the same way. A record of data is essential. It indicates you have been working. In case of doubt, make it sound convincing. Do not believe in miracles, rely on them.
Teamwork is essential in the lab.
It allows you to blame someone else. Always leave room to add an explanation when it doesn't work. Finagle's Laws, Creed, and Motto 1. If anything can go wrong with an experiment, it will. No matter what result is anticipated, there is always someone willing to fake it.