Crystals alone do not establish a complete temperature history. Moisture movement and packaging conditions can affect their appearance, while actual thawing requires a separate assessment.
What the observation tells you
A bag left open can lose quality differently from a sealed pack involved in a power cut. Appearance cannot tell you the exact duration or highest temperature. Calling every crystal 'freezer burn' may also overlook an uncertain food-safety history.
A useful next step
Check dates, packaging and known events, and use official advice where thawing may have occurred. Measure the appliance appropriately. Do not refreeze questionable food merely because some ice crystals remain visible.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.