The general qualifications of a transmitter—such as Islam, sound understanding, accuracy and integrity where required—are not cancelled merely because one person’s report can be accepted in a certain category.
The Ramadan example does not create a universal rule that anyone’s unexamined report is always adequate. Conversely, where a type of judicial proof requires a particular number of witnesses, an excellent character alone does not automatically replace that number.
Keep two questions distinct: Is the person reporting reliable? And what legal form of proof is required for this particular right? A good answer to the first does not necessarily dispense with the second.