setAttributeNS and smil animation elements

Hi all,

In the section A.8.13 Additional accessing rules
(http://www.w3.org/TR/SVGMobile12/svgudom.html#additionalRules) in the
SVG 1.2 spec it says that smil animation elements cannot be modified
once inserted into the model. It doesn't say if this rule only applies
to set(*)Trait or if it also applies to setAttributeNS. Should it be
applied to setAttributeNS? 

If someone tries to modify a smil animation element, with either
set(*)Trait or setAttributeNS, when it has been inserted into the model
what exception should be thrown?

Regards,

Benjamin