The sales guy was wrong, but…
That was, and still is, true with Colt SSA revolvers.
It is also still true of
accurate replicas of the Colt SAA. See, for example, page 9 of U.S. Fire Arms’ PDF brochure on handling their newly manufactured revolvers here:
http://www.usfirearms.com/pdf/USFA_SA_manual.pdf Granted, most SSA replicas nowadays have a transfer bar or similar safety mechanism.
It
was true of Ruger Blackhawks until the 1970’s when the transfer bar system was implemented. Newer Blackhawks are perfectly safe to carry fully loaded – plus Ruger will do a free retrofit of the a transfer bar system for its older revolvers
So the sales guy was wrong in reference to the specific revolver he was showing you.
But such revolvers are still being made and sold. (And I have both a Blackhawk and a Bearcat from the 1960’s that look very similar to newer Rugers, but do not have the transfer bar setup).
Bottom line is that generalities don’t work; the shooter has to know exactly what he has.