Really? The alleged hacker opens up SSH, and then gives a local account for them to gain access through. Gaining access happens to be the unsurmountable part. Yet, with all the assistance, it still took him over 30 minutes!
Fact? Not according to the reference you posted.Sorry? We know for a fact that there are trojans out there that affect Macs and, indeed, have done so. It's been done already.
http://www.cultofmac.com/mac-malware-trojans-are-nothing-new/5124
The fact is no-one cares enough to make trojan writing a mass market exercise for Macs in the same way they do for Windows.