Heel labels: The stitching and shape of the UGG® heel tags look consistent with genuine UGG boots.
Sole pattern: The classic sunburst tread design is correct for older UGG styles.
Interior tags:
The "F19016D / Patent D594,838" tag is standard on older genuine UGGs.
The serial number tag (UGG S/N 1013429) and the QR code are also good signs — most real UGGs made after 2010 include these.
Wool lining: The sheepskin looks plush and real, not synthetic.
This is not typical on most current UGG styles, but it was used on some older or tall models, particularly in the early 2000s and mid-2010s These boots appear to be authentic UGGs, likely an older or less common version of the Classic Tall with a slightly different upper seam pattern. That split at the top is just a style variation.