As a rule, cabinet ministers should be able to tell you exactly what government policy is on any given subject. They all sit at the same table and they each have an obligation to support the policy they collectively decide.
When two ministers say starkly different things, then, you can understand that people tend to notice the discrepancy. The difference usually signals a major problem or controversy and that simply cannot stand. The principle of cabinet solidarity means that in public they must all sing the same song..
It’s bad enough when two ministers disagree. But when the difference is between the Premier and a minister, the matter becomes very serious. If there is one person who must know what government is doing, that person would be the first minister. If there is one person who gets to set government policy, it is the first minister. Everyone else just has an opinion.