Nope, I'm not missing what you're saying, and I tend to agree. However, the law is written in such a way that there is zero burden on the reporter. There is no "level." They don't have to be sure of anything. They don't have to be certain of anything. That's what the investigation is for.
As a reporter, I only need to suspect something is happening/happened. It doesn't matter if 10 other people disagree. It only matters what the reporter suspects, and as long as the report is in good faith and not malicious in nature, there will be zero consequences, zero.
The whole purpose of the law is to get people to speak up about inappropriate situations. If the burden of proof was on the reporter, nothing would get reported for fear of consequences.
If I see/suspect something, I'm going to report it. If it's unproven or unfounded, then so be it. I will have done my job, as required by law, and the rest is out of my hands.