Is there any case law where a police officer was found not to have given adequate Miranda warnings?

It is not, and could not be, contended that the evidence does not support the finding of guilt. On the guilt issue it is argued, only, that evidence of a statement made by defendant after his arrest was improperly admitted because defendant had not been given adequate Miranda warnings. Although the police officer's first recitation of the warnings given was deficient in one respect, his further testimony supplied that omission. We cannot say that the trial court's implied finding of adequacy was without support in the record. In any event, the statement was entirely exculpatory and its admission could by no possibility have been prejudicial. (Chapman v. California (1967) 386 U.S. 18, 87 S.Ct. 824, 17 L.Ed.2d 705, 24 A.L.R.3d 1065).