As Dave is swimming at the local pool, he notices the woman swimming in the lane next to him slips as she tries to get out of the pool. He thinks, "She is trying to get out of the pool too fast." Dave then also slips as he tries to get out of the pool and thinks, "Wow, this poolside sure is slippery!" Here, the difference in explanation is an example of the:

Fundamental attribution error.

Explanation: Fundamental attribution error can be explained as an inclination of thought which explains other peoples behavior, attitude or actions based on internal factors such as personality while given very little possibility to the fact that those actions or attitudes could have been triggered due to external influences caused by physical or situational factors such as weather and so on.

In the scenario above, Dave attributed the woman's slip to internal factor of being too fast without considering that the surface might be slippery(external factor) which he later realized when he slipped.