Found an error:
http://wow.allakhazam.com/db/itemadvsearch.html?itemclass=4%3A1&slot=1&itemname=&binds=-1&minlevel=&maxlevel=&mindps=&maxdps=&speedmin=0.0&speedmax=999.0&effect=0&showall=0&dep=n&source=Live&stat1=0&statval1=&stat2=0&statval2=&stat3=0&statval3=&sort1=healing&sortwt1=1&sort2=spirit&sortwt2=2.214&sort3=stamina&sortwt3=0.5&sort4=manaregen&sortwt4=5.5&sort5=s_red&sortwt5=15&sort6=s_yellow&sortwt6=15&sort7=s_blue&sortwt7=15&sort8=s_meta&sortwt8=15&sort9=0&sortwt9=&sort10=0&sortwt10=&locale=enUS&search=1
Clearly Cowl of Absolution should be ranked higher. It seems that its Healing stat isn't getting counted. Don't know if this is a broader issue or just limited to that item.