Let's take them one by one:
So, according to you, Webb did not know where the gun was at the time his aide came into possession of it. I didn't know that.
Webb's statement at the time.
Also, Webb said that the gun found in possession of the aide was not his. I did not know that.
Webb's statement at the time.
Finally, there was evidently some way for Webb to arrange the release of his aide prior to the aide spending a birthday locked up. I didn't know that.
It may have changed nothing about the time the aide was locked up. But the fact is, Webb didn't try to explain it. Didn't admit the weapon was his, and issued a statement saying (and I paraphrase) "I don't know anything about this."
Look up the news articles from the incident. They all tell the same story.
And, now you know.
And saying "I don't know anything about this" is equivalent to saying "I don't know where my gun was when my aide came into possession of it".
Even these two statements would be contradictory. How can you read both meanings into that one sentence.
How is it not possible to read "I don't know anything about THIS" where "THIS" means "the commission of a crime"? Just what would Webb know about the commission of this crime?