I have a questions about Pasta sauce spoilage
Here are some points to look at:


Was the air seal broken prior to use?
What is the printed shelf-life (or best-by date) in comparison to the date of use?
Are there any detectable (organoleptic) signs of spoilage?
Has the product been stored accordingly as instructed on the label?


Pasta sauce is typically high-acidity, which makes it less prone to spoilage, especially when still within shelf-life / BBD.  This doesn't rule spoilage out completely, and as others have pointed out, more details would definitely help make a more accurate determination.  Strictly speaking, most food packaging do not have zero air permeability, so it wouldn't be unusual to see change in water activity.  If this were for a commercial/industrial application, you could always send it out for lab sampling (or do so in-house), but i'm presuming that isn't likely the case here?