I practice "swings & roundabouts"......... I have gone in late & if anything was said then I just point out that I was working late the night before.
I too am a salaried worker and do not get o/t pay so I just translate the o/t I have to do into the same amount of hours off I take

I suppose it all depends on your relationship with your line manager and that the job your paid to do is getting done .........IF you have to threaten them with OH & S rules then there's a much deeper problem and my suggestion is to have an informal chat with your boss rather than bashing him with OH & S legislation