Inspection of the FODIS output for Hawk (level 1b) suggests that it is uncalibrated (or otherwise incorrect). Spectrum generated (taken from Nigg Bay line 3) is:

(X-axis is band number for Hawk, not wavelength). Graph shape should match solar spectrum (see eg http://fsf.nerc.ac.uk/img/g37_grph.gif) and doesn't.

Some Hawk bands are noisy to the point of uselessness. For example band 71 (1403nm), raw data from Nigg Bay line 3 (attached)

Also see over-water spectrum produced in level 3 image:

Spectrum cannot really be used for anything much - there is no means of quality controlling the data

Data issue occurs over more than one flight, possibly there are sensor problems with some Hawk bands. See eg. Latera band 71, similar to Nigg Bay:

If you plot Eagle and Hawk processed output on the same graph (see attachment) there's about a 30nm overlap for the spectral range, and the instruments don't seem to agree in this overlap. Even if the instruments don't give the same magnitude, the absorption features shown should align (and they don't). This suggests that the spectral calibration of one or both instruments may be out by up to 100nm, which appears to be the displacement needed to make the two graphs align.