I reported a bug to TER but I'm not sure if I described it clearly enough. Do you know how there are a lot of "You are an idiot. You replied to the replier instead of the OP" kinds of posts?  Here's what I told TER:
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BUG REPORT: Improper indents on replies. Indents change depending on which post you click.
(each dash - is an indent level).
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CLICK ON SUBJECT LINE OF ORIGINAL POST AND YOU GET THE CORRECT TREE:
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OrigPost (top post, not indented)
- reply1
- - reply1.1 properly indented under reply1
- reply2 CORRECT PLACEMENT OF REPLY2 (one indent relative to OP)

From the regular board view, select the subject line of "Last post" or choose any post below the OP by clicking on the subject line.  The "clicked" post gets repeated at the TOP of the tree.  E.g., select "reply2" as an example. As you scroll down the tree, reply2 is at the top. Then you see the OP. Scroll down further and "reply2" is INCORRECTLY INDENTED, appearing as a reply to "reply1", not a reply to the OP:
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reply2  (no indent = top level post)
OrigPost (no indent = ALSO a top level post)
- reply1
- - reply1.1
- - reply2 INCORRECT INDENTATION OF REPLY2 (appears as a reply to reply1)
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If you can explain that (and variations) in a better way, please do so.  Once you have tags regarding which post you have replied to, I don't why the position should change with the clicks described.