9.4 checksum errors in recovery with gin index

When recovering from a crash (with injection of a partial page write at
time of crash) against 7c7b1f4ae5ea3b1b113682d4d I get a checksum
verification failure.

16396 is a gin index.

If I have it ignore checksum failures, there is no apparent misbehavior.
I'm trying to bisect it, but it could take a while and I thought someone
might have some theories based on the log:

29075 2014-05-06 23:29:51.411 PDT:LOG: 00000: database system was not
properly shut down; automatic recovery in progress
29075 2014-05-06 23:29:51.411 PDT:LOCATION: StartupXLOG, xlog.c:6361
29075 2014-05-06 23:29:51.412 PDT:LOG: 00000: redo starts at 11/323FE1C0
29075 2014-05-06 23:29:51.412 PDT:LOCATION: StartupXLOG, xlog.c:6600
29075 2014-05-06 23:29:51.471 PDT:WARNING: 01000: page verification
failed, calculated checksum 35967 but expected 7881
29075 2014-05-06 23:29:51.471 PDT:CONTEXT: xlog redo Delete list pages
(16), node: 1663/16384/16396 blkno: 0
29075 2014-05-06 23:29:51.471 PDT:LOCATION: PageIsVerified, bufpage.c:145
29075 2014-05-06 23:29:51.471 PDT:FATAL: XX001: invalid page in block
28486 of relation base/16384/16396
29075 2014-05-06 23:29:51.471 PDT:CONTEXT: xlog redo Delete list pages
(16), node: 1663/16384/16396 blkno: 0
29075 2014-05-06 23:29:51.471 PDT:LOCATION: ReadBuffer_common,
bufmgr.c:483
27799 2014-05-06 23:29:51.473 PDT:LOG: 00000: startup process (PID 29075)
exited with exit code 1
27799 2014-05-06 23:29:51.473 PDT:LOCATION: LogChildExit,
postmaster.c:3281
27799 2014-05-06 23:29:51.473 PDT:LOG: 00000: aborting startup due to
startup process failure

Cheers,

Jeff