They both have a good point.
When I first read the facts of the case, my reaction was the same as Judge Trott's. A defendant can be convicted of perjury even if he's acquitted at the underlying trial. They're two separate offenses. They have distinct elements. Double jeopardy doesn't apply. So, I thought, when X takes the stand and says "Y isn't true", X can thereafter properly be convicted of perjury when Y is true and X knew it. Even if X got off at the original trial.
But, upon reflection, I think that Judge Reinhardt has a point. He argues that, at least in some cases, double jeopardy should bar the subsequent perjury prosecution. Because, otherwise, the government could basically commence multiple prosecutions over the same basic offense. And, though he doesn't make this point, the regression here could potentially be infinite. X gets up at his trial for murder and testifies "I didn't do it." He's acquitted. Then the government brings a perjury prosecution, claiming that X lied when he said he was innocent. X then takes the stand at the second trial and says "I didn't lie; I really didn't do it," is acquitted, and the government then brings a third prosecution. Ad nauseum.
So I originally thought that, had O.J. testified, a perjury prosecution would have been entirely proper. Now, after reading Judge Reinhardt's opinion, I'm not so sure.
Mind you, this would all be irrelevant if thecourts properly applied collateral estoppel principles to criminal cases. But we don't. At all. Starting with Blockburger in 1932 and up to the present era. Hence we have the double jeopardy problem here.
In the end, like Judge Wardlaw, my own views on the subject probably come closer to Judge Reinhardt than Judge Trott. I'd have written a slightly different opinion than my former boss (including, ironically enough, that I wouldn't have been nearly as defensive as he was, though I imagine that some of that was probably just for Judge Wardlaw's comfort). But, in the end, I would probably have come out the same way.
P.S. - Another small difference. Unlike Judge Reinhardt, I wouldn't have gratuitiously slammed -- hard -- the prosecution in the O.J. Simpson case. Make sure to read the conclusion of footnote 6 (on page 2107) for Judge Reinhardt's comment about "the unprecedented imbalance in legal skills between the Dream Team and the prosecution" therein. Oh, and, unlike Judge Reinhardt, I wouldn't have made reference to the fact that "the glove didn't fit". I'm pretty damn sure that it did.