diff --git a/conformance/compare.py b/conformance/compare.py
index b3c944a..ec568b5 100755
--- a/conformance/compare.py
+++ b/conformance/compare.py
@@ -239,7 +239,8 @@ for rel in files:
             "caught": [(p, w, m[:2500]) for p, w, m in caught_panics[:3]],
             "n_caught": len(caught_panics),
         })
-    for kind, detail, key, rec in issues:
+    # A ref-bug file's differences are listed with the evidence instead.
+    for kind, detail, key, rec in (issues if cls != "ref-bug" else []):
         if kind == "our-error":
             add(root_causes, norm(key), rel, detail[:300])
         else:
diff --git a/conformance/report.py b/conformance/report.py
index 6c4cb13..0770936 100644
--- a/conformance/report.py
+++ b/conformance/report.py
@@ -225,9 +225,8 @@ for c in sorted(by_corpus):
 w(f"| **all** | **{len(rows)}** | " + " | ".join(f"**{total.get(k, 0)}**" for k in CLASSES) + " |")
 w("")
 nonok = total.get("our-error", 0) + total.get("mismatch", 0)
-w(f"**Our errors and mismatches: {nonok}.** "
-  + ("Every file clawhdf5 does not read like h5py is either unreadable by h5py or a confirmed libhdf5 "
-     "bug (*ref-bug*)." if nonok == 0 else "See the root causes below.")
+w(f"**Our errors and mismatches: {nonok}.** Files not ok: "
+  + (", ".join(f"{total[c]} {c}" for c in CLASSES if c != "ok" and total.get(c)) or "none") + "."
   + (f" {len(ref_fixes)} object(s) were compared against h5py's values corrected for a known h5py bug"
      f" ({sum(1 for x in ref_fixes if x[3])} identical to clawhdf5's; see *Reference bugs*)." if ref_fixes else ""))
 w("")
@@ -250,19 +249,25 @@ w("")
 
 w("## Our-error root causes")
 w("")
-w("Grouped by normalised error message. *files* counts files whose class this cause affects.")
-w("")
-w("| files | objects | error | examples |")
-w("|---:|---:|---|---|")
-for k, v in res["root_causes"].items():
-    w(f"| {v['files']} | {v['count']} | `{k.replace('|', '/')}` | {ex_list(v['file_list'])} |")
+if res["root_causes"]:
+    w("Grouped by normalised error message. *files* counts files whose class this cause affects.")
+    w("")
+    w("| files | objects | error | examples |")
+    w("|---:|---:|---|---|")
+    for k, v in res["root_causes"].items():
+        w(f"| {v['files']} | {v['count']} | `{k.replace('|', '/')}` | {ex_list(v['file_list'])} |")
+else:
+    w("None.")
 w("")
 w("## Mismatch root causes")
 w("")
-w("| files | objects | cause | examples |")
-w("|---:|---:|---|---|")
-for k, v in res["mismatch_causes"].items():
-    w(f"| {v['files']} | {v['count']} | `{k.replace('|', '/')}` | {ex_list(v['file_list'])} |")
+if res["mismatch_causes"]:
+    w("| files | objects | cause | examples |")
+    w("|---:|---:|---|---|")
+    for k, v in res["mismatch_causes"].items():
+        w(f"| {v['files']} | {v['count']} | `{k.replace('|', '/')}` | {ex_list(v['file_list'])} |")
+else:
+    w("None.")
 w("")
 
 w("## CVE corpus: clawhdf5 vs h5dump vs h5py")