Oops, calls and constructions had the same problem.

index.bs

@@ -14275,7 +14275,8 @@ described in the previous section).
         |callResult| and jump to the step labeled <a href="#invoke-return"><i>return</i></a>.
     1.  Set |completion| to the result of [=converted to an IDL value|converting=]
         |callResult|.\[[Value]] to an IDL value of the same type as the operation's
-        return type.
+        return type. If this throws an exception, set |completion| to the completion value
+        representing the thrown exception.
     1.  <i id="invoke-return">Return:</i> at this
         point |completion| will be set to an ECMAScript completion value.
         1.  [=Clean up after running a callback=] with |stored settings|.
@@ -14317,7 +14318,8 @@ a return type that is a [=promise type=].
         |callResult| and jump to the step labeled <a href="#construct-return"><i>return</i></a>.
     1.  Set |completion| to the result of [=converted to an IDL value|converting=]
         |callResult|.\[[Value]] to an IDL value of the same type as the operation's
-        return type.
+        return type. If this throws an exception, set |completion| to the completion value
+        representing the thrown exception.
     1.  <i id="construct-return">Return:</i> at this
         point |completion| will be set to an ECMAScript completion value.
         1.  [=Clean up after running a callback=] with |stored settings|.