I don't think it was the Others that reported the plane found... and no survivors. I think it may have been Hanso (who funded the Dharma initiative) or Widmore (Penny's Dad, and owner of the company that makes the pregancy tests, and the balloon the real Henry Gale was using among other things).
Remember how Ben said that he would activate the implant in Claire? Maybe Patchy had one of those implants, and that is why he appeared dead to Kate and the gang.
I certainly hope that it isn't anything to do with pergatory. The writers and producers have stated that it wasn't, and it would seem like a cop-out.