Poster edited the question in such a manner that it became hard to identify the original problem

Question

Reccently I came across this phenomenon: In some questions, the mistake that led to the question was pointed out by other users due to either someone answering the question or pointing out the mistake in the comments. The Original Poster then edited the question to hide the mistake. This removed the purpose of the question, making it difficult to understand the answers or made it difficult to answer the question. What is the best thing to do in these situations?

For example:

1. Why should we not change inputs to a sequential circuit (Moore machine) at the clock edge? Here the original poster edited the question to make the problem less obvious. Only when looking at the previous version in the edit history, the problem becomes obvious.

2. Asynchronous reset within always block - BLOCKING vs NON-BLOCKING assignment In this case, the question was edited after it was answered, making the answer look confusing to other readers.

I have 2 suggestions:

1. Locking questions that have been answered so that users cannot change the question without moderator's permissions.
2. Make it easier for other (trusted) users to roll back questions.

Please give more suggestions or shed light on the policy of the community on these situations, so we can know what has to be done in such a situation.

Answer 1

It is already easy to roll back edits. Here is what it looks like for me when I look at the edit history for your second question. The first revision has a dedicated rollback button.

Any user with a reputation score of at least 2000 should see it, but it may be hidden for peons new users.

However, I really don't see the problem with either of these questions. The edit history for the first one does not show anything other than typo and grammar corrections, and the second one didn't seem to change the meat of the answer.