No AI detectors do a great job yet. They are mildly to terribly inaccurate. I wouldn't worry about this.

Unique should signal an "if and only if", hence two-way relationship.

So, diagramming as follows:

1- HSE -> Leave Mark

2- HSE -> Implement

3- All Others ( or /HSE) -> /Implement

Contra of 3: Implement -> HSE

Combine 1 and 3, tying in 2:

Implement <-> HSE -> LM

So C MUST be true. All the rest could be true or false or whatever.