Nick Reiner had an eventful day in court … he’s now being repped by a public defender and his outgoing defense attorney made it clear he thinks Nick is NOT guilty of murdering his parents … but the way Alan Jackson made his statement has our antennas up.

We got into every angle of Nick’s appearance in a Downtown Los Angeles courtroom Wednesday on “TMZ Live” … the change of lawyer, an interesting statement from the D.A., a possible defense strategy, and we even had a reporter inside the courthouse who told us how Nick was acting.

The big thing here is Jackson is out, and a public defender is in … but Jackson left some breadcrumbs that seem to indicate Nick’s got a strategy ready and a new defense team may be coming in to take over.

Based on the way Jackson said Nick wasn’t guilty of murdering Rob and Michele Reiner, it sounds like Nick is going to plead not guilty by reason of insanity … something we’ve told you about for weeks now. Listen again to Jackson carefully — he says, “pursuant to the law in California Nick Reiner is not guilty of murder.”

Nick’s new public defender is Kimberly Greene … but if Nick is going to go with the not guilty by reason of insanity defense, it’s a good bet he will need a new defense team with the resources to call in experts to mount that defense … something a public defender just can’t do.

Inside the courtroom, our Alexa Klohn had eyes on Nick … and she says he seemed calm, cool and collected … and even curious about all the media covering his every move.

After Jackson told folks to “take it to the bank” that Nick is not guilty, it was Nathan Hochman‘s turn to speak … and the Los Angeles County District Attorney said prosecutors were confident a jury would unanimously find Nick guilty of murdering his parents.

Hochman’s rebuttal was strong, but we explain why it’s kind of a strange statement for the D.A. to make at this point in the case.