Possible bug in GDAL?

Given this file:

http://mtarchive.geol.iastate.edu/2019/02/18/mrms/ncep/GaugeCorr_QPE_01H/GaugeCorr_QPE_01H_00.00_20190218-150000.grib2.gz

… I get different output depending on the software I use.

wgrib2 2019021815.grib2 -csv wgrib2.csv

and

cdo outputtab,date,time,lat,lon,value 2019021815.grib2 > cdo.txt

both output:

-3 (undefined) :  8,869,250 records
0              : 14,848,865 records
Other values   :    781,885 records
___________________________________
Total          : 24,500,000 records

However:

gdal_translate.exe -of xyz 2019021815.grib2 gdal.csv

outputs -3 for all 24,500,000 records.

I get the same result if I parse the file using Python + GDAL.

Is this a bug in GDAL? I'd like to be able to parse these files using Python.

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