The security people knew about the hole in the fence. Instead of the hole being repaired, it was covered with a tarp.
We don’t know when the hole was cut. It’s just as much a chance that those base jumpers cut the hole themselves as not. If you were found to have done something illegal, would you admit to anything more than what could be proven you did?
Also, it is possible the security did take note of the hole, but the uppers nixed fixing it for some reason as is often the case.