A similar incident actually happened to me. I live in an apartment style condo & the neighbor across the hall died during a nap and had been dead for a few hours before anyone noticed. The tenant was in her 60s & had lived there with her boyfriend for about 30 years. His daughter was visiting when they discovered her. When the firemen arrived, they suggested the daughter take her father to her house. When the police showed up they asked everyone who entered the building to stay out of the hallway as much as possible.
You staying would have only made you late for work & done little to help anyone.
You did what you should have.