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.
From what little I know about BASE jumping I learned from one of the jumpers referred to in the attached article.
They know full well that when they BASE jump that they are trespassing, and could get caught and ticketed. One thing that they never do is cause damage to whatever structure they are jumping from, as that would add destruction of property to any charges if caught.
They scout jump areas for several days, trying to find the best way in and the best way not to get caught. That tells me that the hole in the fence had been there at least a week. These guys admitted going around a tarp covering the hole. (And no I don’t think they cut the fence previously, hoping it wouldn’t get fixed)
Since security and the uppers knew about the hole since at least mid-September, you would think that area would be patrolled just a tad bit better.