Adventure, sure, maybe a bit annoying for this grown-up

OK, I read Island of Thieves by Josh Lacey.  It is advertised as "Treasure Island meets James Bond." And, there is plenty of action.  The premise is that Tom Trelawney was scheduled to spend time with a buddy while his very boring parents take a much-needed vacation.  That is until he burns down his shed...suddenly, his friend's parents aren't so keen on his company.  A last minute scramble sends him to his Uncle Harvey in New York City.  His irresponsible uncle promptly tells him he's leaving him alone in NYC because a he has "urgent business" in Peru.  You guessed it, Tom manages to force his way along on what turns out to be a treasure hunt.  They follow clues, escape captivity, evade a drug lord and chase history.  As far as excitement goes, it lives up to the promise.  As an adult, however, the irresponsibility meter is pegged.  I have read many books where the kids act like grown-ups...from Harry Potter to Call it Courage, so I accept the premise.  However, when Tom has to shoot one of the drug lord's henchmen (in the leg), it seemed to take the fun out of it.  Maybe I'm getting too old...