Trivial: On sanitize_records.pl help and perldoc say the option is --auto_search, but on usage we can find that the real option is with slash, not underscore: --auto-search. BTW, is not clear what does this script, what errors look for, if only "&" (without looking the code, of course).
Fixed by bug 17196: http://git.koha-community.org/gitweb/?p=koha.git;a=commitdiff;h=2096876b36e466becf589cc9433822a57db379a8 *** This bug has been marked as a duplicate of bug 17196 ***