I will need to rewind as I missed the breathtaking moment itself. But I suspect Blackwell showed the slide that IS an already allowed exhibit for the defense but had to question carefully so that Tobin didn't refer to the portion that showed the testing was actually done as part of the autopsy specifically.
This info was out there for both sides. It is not new. The problem began when Fowler began to opine on carbon monoxide when the state was not informed he would be doing so and therefore they were not prepared to challenge that testimony. That in turn caused Baker to say hey, wait, look at this, on the defense exhibit, this says that testing was done, did you guys (state) introduce it? (aha moment) so the state tried to get it in and was denied)