Your post reminded me about asking about the practice, Andy. There tends to be a dog-piling act where more than one mod will come in after the act to essentially speak their mind and it's typically not favorable to the OP's point or to another member's point.
We all disagree on stuff from time to time, but how does not just posting "Thread Closed" and perhaps a short and non-directive explanation as to why become less desirable than basically throwing in another opinion when you're not going to allow the OP or other members to speak to that opinion, even in a TOS-appropirate manner? How exactly does that further the objective of making this place less hostile?
I see your point, though the specifics in this case weren't super clear. Tim locked the thread but I don't think he was certain what else he might do with it. It might have been re-opened, it might have been moved.
Meanwhile, I checked my subscribed threads list, saw activity in the thread, didn't notice the lock icon and clicked to the first unread post. Looked like an open thread to me, so I replied. Learned later the thread was locked. Decided to let my post stand.
Crash analysis should be a place where a rider can post honestly and not be attacked. I've felt that way forever. The difference this time is the rider isn't being honest and is even revising his account to avoid taking responsibility for the crash. The thread should really be in General and re-opened, if you ask me.