Nobody seems to have pointed out that a 21-year-old whisky remains a 21-year-old whisky however long it's sitting at the back of a cupboard (or, in this case, garage).
The 'age' of a whisky is the length of time it spends maturing in casks (and thus absorbing the flavours of the wood and whatever was previously in those casks, such as port or sherry).
While Patrickstar might have what's now a very rare whisky, it's still a 21-year-old one, not a 50-year-old one.