A witness statement is evidence. Evidence isn't only things you can touch. A photograph isn't any more evidence than a witness statement is. A photograph isn't inherently more credible than a witness statement. You should consider the credibility of each piece of evidence regardless of what type of evidence it is.

A statement made by a trustworthy employee should be taken seriously, "he said she said" is not a valid excuse to not make hard decisions.

Sure but if it is denied by the other employee, you've got directly contradicting evidence. That's what "he said she said" is.

I suppose the right word is "hard evidence." And yes I would say a photograph is, in general, more credible than a witness statement.

I say this as someone who just went through a long trial (representing myself, while the other side had an attorney), with a lot of "he said she said", and where a tape recording (of a violent attack on me) and photographs (of bruises) made all the difference.

Recently the cases that have hit the news, have rarely been borderline grey areas.

If someone comes forward it is because they are being serially harassed, have documentation to back it up, and there are multiple other people who have also been victims.

He said she said situations will likely result in a warning or no action at all.

That's why I'd recommend people make recordings. The tough thing is, in California, it is illegal to record unless you have their permission, or if it is a felony in progress. (which it was in my case)

That is not what "he said, she said" means.

Witness testimony is the weakest form of evidence. It's foundationally unempirical.