GPT processing of Sentinel-1 produces invalid NetCDF image

is a very big number, so likely the fictional creation of some bug in the reader.

You may have seen:

Support for NetCDF4-CF has improved in recent years as more people use it and find issues. If you still encounter problems they should be reported to the upstream developers.

Normally, applications ignore metadata they don’t use. There have been issues with applications that target smaller files and can’t handle large data sets.

NetCDF4 is a subset of HDF5. It would be interesting to know
if the “Unexpected end of file” error occurs when you load it as
HDF5 in applications widely used with HDF5/NetCDF4 data (HDFview, Matlab, IDL, etc).

It may be helpful to check how various widely tools interpret NetCDF4 metadata (e.g., using ncdump -h, gdalinfo, cdo info) for the two files. All these have large user communities so someone may recognize your issue.