Your relative, when providing you with oral family history information, may easily get events in the wrong order. The details they remember, with the exception of the order in which they happened, may be perfectly correct.
The order in which things happened does matter because a correct time frame matters at least most of the time. If two events are completely unrelated to each other, it can be even easier to confuse the order in which they happened.
When talking to a relative, focus on what they can remember. If the order in which things happens seems a litle wonky, concentrate on getting as much information as you can from the person and recording their rendition as accurately as you can.
Then when you analyze the oral history you can start looking at the specific ordering of events.