Most States document on a driver's motor vehicle records (MVR) if an accident has occurred involving them, but typically do not assign fault. In Washington State, collisions involving non-commercial vehicles remain on a person's the driving record for 5 years from the collision date. Collisions involving commercial vehicles stay on the record for 10 years.

Washington records accidents on your driving history to show involvement, but the WA Department of Licensing (DOL) does not determine fault for the collisions.

As for your son's Nevada speeding ticket, both NV and WA are members of the Drivers License Compact which means that Nevada's DMV should transfer the information concerning the traffic violation to Washington's DOL.

Some states that are part of this Compact decide not to assess points or put the out of state violation on the person's driving record, but others do. For example, Nevada has decided to not assess points for out of state traffic convictions. The NV officer might know that WA does not record out of state tickets but your son can check with DOL to be certain.