| Across | Answers and Clues | Explanations |
| 1 | PARAPHRASE | |
| Expected rash developed in ape, say, in a different way (10) | PAR + (anagram of RASH inside APE) | |
| 6 | SWAB | |
| Specimen was treated with boron (4) | Anagram of WAS + B | |
| 10 | SHAKE | |
| Small fish flourish (5) | S + HAKE | |
| 11 | TRIENNIAL | |
| Nine involved in court case lasting three years (9) | Anagram of NINE inside TRIAL | |
| 12 | AIRMAN | |
| Bomber’s guide, for one, married in a Middle East country (6) | M inside (A + IRAN) | |
| 13 | GROWS UP | |
| Gets bigger ewes evenly distributed in flock (5,2) | e(W)e(S) inside GROUP | |
| 15 | LIGHTS | |
| Flimsy pole catches fire (6) | LIGHT + S | |
| 16 | BEATINGS | |
| People gathered around at events associated with strikes (8) | BEINGS outside AT | |
| 17 | STRICTLY | |
| Trick not completed ahead of time in secret precisely (8) | [(TRIC)K + T] inside SLY | |
| 20 | SORTIE | |
| Offensive act that is committed after class (6) | IE after SORT | |
| 23 | EMPEROR | |
| Coinage of Rome sent around by ruler (7) | Anagram of ROME inside PER | |
| 24 | ROLLED | |
| Half of patrol went ahead and turned (6) | part(ROL) + LED | |
| 26 | INSOLVENT | |
| Lions sprayed discharge on the rocks (9) | Anagram of LIONS + VENT | |
| 27 | BLAZE | |
| Stand around after start of big bonfire (5) | LAZE after (B)IG | |
| 28 | GUST | |
| Endless enthusiasm is a blast? (4) | (GUST)O | |
| 29 | STARTER-KIT | |
| Leading person arranged trek with IT equipment crucial to initial success (7-3) | STAR + anagram of TREK + IT | |
| Down | Answers and Clues | Explanations |
| 1 | PAST | |
| Forgotten or missed by minister (4) | PASTOR minus OR | |
| 2 | REARING | |
| Auditor engaged by organisation is setting up (7) | EAR inside RING | |
| 3 | PNEUMATIC DRILL | |
| Pictured man injured badly with air-tool (9,5) | Anagram of PICTURED MAN + ILL | |
| 4 | RATING | |
| Cheap newspaper making case to preserve status (6) | RAG outside TIN | |
| 5 | SHINGLE | |
| Doctor’s sign, say, individual spotted on the outside of hospital (7) | SINGLE outside H | |
| 7 | WAITS ON | |
| First of all it’s breaking accomplished serves (5,2) | [(A)LL + ITS] inside WON | |
| 8 | BILLPOSTER | |
| Advertiser is beginning to blame sick mail handler (10) | (B)LAME + ILL + POSTER | |
| 9 | UNCONTROLLABLE | |
| Furious relative checking on bill containing bread (14) | UNCLE outside [(ON + TAB) outside ROLL] | |
| 14 | BLISTERING | |
| Very hot tiles warped in transport (10) | Anagram of TILES inside BRING | |
| 16 | BAY | |
| Dark horse’s stall (3) | Double Definition | |
| 18 | RAPISTS | |
| Criminal charge is restricting street people responsible for violations (7) | (RAP + IS) outside ST | |
| 19 | LARGEST | |
| Most prominent home of Hollywood gangster primarily owned by others (7) | LA + [(G)ANGSTER inside REST] | |
| 21 | TIE RACK | |
| Wardrobe feature, possibly, that is fixed in a permanent way (3,4) | IE inside TRACK | |
| 22 | CRATER | |
| Packing case, located by river, is hollow (6) | CRATE + R | |
| 25 | DEFT | |
| Expert took food over time (4) | FED reversed + T |
I’m still not convinced about the “dark” or “dark horse” being a bay. A “horse’s stall” is a bay, and so is a “stall”. Many horses are bays, but I understand the colour is a brown which I would describe as medium if I had to differentiate. To me a dark horse is darker than a bay. However I have not exhaustively reviewed all the possible resources in this.
I wrote this before reading insights, which refers to the resources available to the setter and the solver. Perhaps if I had persisted for longer or knew where else to look, I would have found a response to convince me of the above.
I would commend David’s insight to all solvers. Over a period of time we will all gain a deeper knowledge “Insight into” the workings of crossword clues, setters, and solver limitations. I certainly take away something almost every week.