As far as I'm aware LH didn't break any rules, thus shouldn't be DSQ'd.

MB and DC asked the question when commentating that if the plank was worn away beyond legality by damage, would this result in a penalty? I'm not sure of the rule here so I'd be interested to know whether this an 'accident damage' clause or not. If there isn't, then luckily Lewis' car couldn't have been worn beyond legality otherwise he would have been DSQ'd.

As for the safety hazard thing, If parts had started flying off then he should have been told to stop, but this didn't seem to be the case and performance was clearly not enhanced, so it seems the stewards got it right here.