Wrong data for TIFF images

Example:

ImagePlus img = new ImagePlus(tiffFile);
L.i(img.getWidth()+" x "+img.getHeight());
for (int i = 500; i < 600; i++) {
int[] px = img.getPixel(i, i);
out.println(i+": "+Arrays.toString(px));
}

Dimensions are always correct, data is correct for other image formats, but for TIFFs (here, 16 bit uncompressed) only the first channel shows values > 0, which is incorrect:

6000 x 4000
500: [122, 0, 0, 0]
501: [65325, 0, 0, 0]
502: [65471, 0, 0, 0]
503: [28, 0, 0, 0]
504: [65202, 0, 0, 0]
505: [65281, 0, 0, 0]
506: [65021, 0, 0, 0]

How can I get correct values?

Start at the ImagePlus(tiffFile) loading path and follow getPixel for 16-bit uncompressed TIFF data, comparing it with the behavior for other image formats. Reproduce the 6000 x 4000 example and verify that all returned channel values match the TIFF pixel data rather than only the first channel being populated.

Written by the indexing model from the issue text.