+  (if (and (consp form)
+           (eq '\, (car form))
+           (consp (cdr form))
+           (null (cddr form)))
+      (cadr form)))

There's nothing wrong with this code. But, just FYI, here's what it would
look like with pcase (assuming I didn't mess up writing this on my phone).

(pcase form
  ((`\, x) x))