It looks to me as though this thread can be summarized this way:

1. gzip's warning when the size overflows 32 bits should not force a nonzero
   exit status.

2. The warning should read something like the following:

   The size, > 4 GB, is being recorded modulo 4 GB. Decompression will check
   that the size is correct modulo 4 GB. Nothing bad is happening. Just
   thought you might like to know.

:)

-Chap