Appeal proofing decisions is a common practice of trial judges (and even intermediate appellate court judges and state supreme court judges) well known to practitioners and even discussed by law professors in class at times, but I'd have a hard time coming up with a reference where it was discussed.
There is probably a law review article that discusses the practice somewhere.
It also comes in several versions.
One is to make copious findings of fact (especially on credibility) that are hard to reverse on appeal. A judicial finding that someone had an intent to defraud another party based upon his demeanor when he testified about that issue can overcome all sorts of technical objections to a claim in a lawsuit on a more strict liability basis like breach of contract.
Another is to give a "soon to lose" party everything he wants procedurally, even when he isn't entitled to it so he can't appeal on procedural grounds. For example, a court might admit otherwise inadmissible evidence over the objection of the other party and then rule against the party seeking to admit that evidence anyway on the merits. Lawyers often assume that this is happening when a judge starts making blatantly incorrect rulings on procedural issues against them repeatedly in an otherwise strong case in a bench trial.
A third is to provide an alternative holding that reaches the same conclusion in case for a different legal reason in the event that an appellate court does not agree with the primary holding.
A fourth (mostly limited to appellate contexts) is to decide a case on grounds that make the case uninteresting to review on further appeal (e.g. finding that a factual conclusion is supported by evidence in the record, or that an issue wasn't preserved adequately in a trial court) or beyond the jurisdiction of other courts (e.g. deciding a case based upon state law so that the U.S. Supreme Court won't review it).
