The 'current_md5' md5sum in the logfile is the md5sum *after* bspatch (when the patch fails because of a checksum mismatch, it's probably the same checksum as *before*, though, AFAIR, bspatch gives up on a checksum error).
'expected_md5' is the correct md5sum of the patched file (ie. at v3.0.3)
'patch_md5' the md5sum of the patchfile.
The correct md5sum of this file from a vanilla 3.0.2 install is actually
de56a93374824125a600e3f8bbb08957
(You can confirm this with a grep etc/sysconfig/iptables /test/diags/factory/rootfs_md5_list)
Check
this post for a working file from a vanilla 3.0.2 dump.
So, yeah, it does look like your file has been modified

.