Frank, if you'll take my reply to this on board in the spirit it's offered, there are exceptions to every general rule. However, all important cases from Crown Courts are reported in the legal press in the interests of open justice. Believe me, firearms appeals where costs are awarded against a Chief Constable (CC) are so rare they are hot news, and become part of case law. Judges in lower courts then follow them, and every KC relies on them on behalf of their clients.
You've made a vague claim of two instances where costs were awarded to successful claimants. I believe this only occurs where the court rules that a Chief Constable acted unreasonably, or 'perversely' as Uncle Norm so neatly put it. If you care to quote the name of appellant, and the approximate year then if I can I'll find the judgment, and post a link to it so everyone can re-assess their chances. Your post sounds very unlikely in view of #51 above.
The case cited below is a High Court appeal from a decision of a Crown Court (you may need to cut & paste the whole link). There are many other cases like it, and transcripts for all of them are available. This case illustrates the legal principles a court follows in determing whether refusals and revocations of firearms certificates by a CC are justified, and how to decide related issues like costs. It might be of interest to some on TSD to see many of the factors involved, and inform themselves generally.
I can do similar searches, but if you've already got a link to your instances then please post it to save me time. If you can't supply enough basic facts to enable a search of the law databases online then your assertions are hearsay so unreliable. I won't use the term bull**** because it's easy to misinterpret judgments, which don't always say what they seem to.