The Pope asked him to do it and assigned people to ensure known references, connections, and usage were taken to account.
Chapters were reviewed as they were completed looking for problems, and making sure past Hebrew past usage in earlier approved writings were taken into account in the Latin commentary. a'Lapide was the Hebrew scholar of his day and prior Jewish interpretation was very important to him.
Everything was reviewed and approved by proper Church authorities which in and of itself makes sure it's not "his private interpretation".
But its apparently not a definitive interpretation, right?
This sounds like a global warming paper being reviewed by global warming scientists.
You say that "proper church authorities" were used ... who determined those authorities were the authorities?
When it comes right down to it ... someones interpretation was inspected by a bunch of other exegetes, and those exegetes conferred their blessing on the interpretation ... or they witheld their blessing.
Protestants do the same thing every day ... except we have the added difficulty that our interpretations are inspected by exegetes that we already know will not agree with us ... so our exegesis has to be better and more complete.