Hi Pos, That could happen....but to have that occur you have to violate another portion of the codes. The one about all exposed metal parts need to be either double insulated from contact or earth grounded. The failed transformer should be one or the other and then there is no hazard.

The resistor is actually best thought of as a low frequency path for crud between the circuitry and earth. Many designs leave it out. I find that it helps with the S/N a bit. Also the use of a large rectifier (often a bridge) between the two grounds could fail if there is the second grounding violation. I don't care for the rectifiers as they leave the chassis about 0.7 volts different from the earth and 0.7 Volts is a lot of potential noise that is not eliminated.

Just my two cents on how the codes work.