Although the NCD on the unaffected vehicle will remain in tact, the fact you will have had a claim will mark you as a risk ( even if the claim was made for a parked vehicle !) and will push your premiums up for ALL insurances
This is why the reality is there is no such thing as protected NCB and it is a n utter waste of money.. Sure, your NCB might still be 60% of whatever, but your next insurance quote will have a massive ( say, 60 % !! ) loading as you have had a claim
The insurance companies really ought to be brought to heel by legislation as they simply make up the rules to suit them selves