Beyond the question of “Does LE have DNA” next comes “Does it consist of a full and complete DNA profile”?
Just my guess, crime scene forensics was unable to obtain a full DNA profile because of the outdoor crime scene undiscovered until the following day, additionally involving a creek (wetness/water). A partial profile can be used to eliminate certain POIs but it wouldn’t identify any one person or be useful in identifying close relatives via familial testing. I think this is the reason for the wiggle-wobbling over if LE has DNA or not. A partial DNA profile could also be the reason that LE have stated mentioning the “reddish-brown hair” and maybe even “not blue eyes”, if those certain DNA markers were indeed present.
About the difficulty encountered when processing outdoor crime scenes -
Collecting DNA Evidence at Outdoor Crime Scenes
Outdoor Crime Scene
Home > 2. Crime Scenes > Outdoor Crime Scene
An outdoor crime scene is the most vulnerable to loss, contamination and damaging effects on biological evidence in a short period of time. Individuals with access to the scene can potentially alter, destroy or contaminate evidence. The risk is greatest when the crime scene is not properly secured.
Destruction or deterioration of evidence due to environmental conditions, such as heat, cold, rain, snow and wind call for rapid and effective protection of biological evidence. Evidence that cannot be protected under these conditions should be quickly collected without compromising its integrity.....