%destructor doesn't destruct what can be destructed by user actions

[Setzer, Sebastian \(ext\)]

Hi,
The bison-manual (for example
http://www.gnu.org/software/bison/manual/html_mono/bison.html) states:
"Right-hand size symbols of a rule that explicitly triggers a syntax
error via YYERROR are not discarded automatically. As a rule of thumb,
destructors are invoked only when user actions cannot manage the
memory."

Should be "Right-hand side..."?

In the Calc++ - example, this user-action doesn't free the memory:
    | "identifier"  { $$ = driver.variables[*$1]; }
so this example will leak?

Best regards,
Sebastian Setzer