Select 5 random rows based on certain criteria

I want to get 5 random cases per Agent from a RawData where [Reviewer] = 'G'. If an agent does not have 5 cases that match this criteria then take the required number of random cases where [Reviewer] = 'P'

• John has 5 cases where [Reviewer] = 'G' so these 5 cases should appear in the results
• Dan has 2 cases where [Reviewer] = 'G' so 3 random cases where [Reviewer] = 'P' should be included in results
• Pat has 6 cases where [Reviewer] = 'P' so 5 random cases should be in the results
• Mary has 2 cases where [Reviewer] = 'G' so 3 random cases where [Reviewer] = 'P' should be included in results
• Joe has 1 case where [Reviewer] = 'G' and only 2 cases where [Reviewer] = 'P' so all three cases should be included in results

Raw Data & Example of desired results