Possible bug in YOLOv3 model?

[weimingzha0]

In yolov3-10.onnx (from https://github.com/onnx/models/tree/master/vision/object_detection_segmentation/yolov3 ), the post-processing part includes 6 loops. The trip counts are 13, 13, 26, 26, 52 ,52, respectively.

The loops uses scan outputs. The problem is, by ONNX definition, loop output is like "[1, 2, 3, 4...TripCount]. However, for this model, it expects the output to be like "[0, 1, 2, 3, .. TripCount-1]"