Expressions such as 'development of doctrine', a 'deeper understanding' and the like, I suspect include changes in doctrine and very often complete reversal of it. Legitimate doctrinal development usually takes place when a doctrine is attacked thus the Council of Trent reasserted dogmas, doctrines and practices which the Protestant Reformers rejected.
Revelation finished with the last Apostle, since then no new truths have been discovered or revealed. Scientific knowledge has increased steadily over the millennia not because the Holy Spirit is revealing it but because man is using his God-given intelligence to build on what previous generations have learned before. What is understood increases rather than evolves, I would say. Science endeavours to explain the physical world around us and contributes nothing to that which we can call a moral law: that has been revealed to us by the Holy Spirit through Scripture and the Tradition handed down from the Apostles.