The competent authority shall make a brief memorandum of the substance of the evidence of every witness as the examination of the witness proceeds, and such memorandum shall be authenticated under the hand of the competent authority or in the manner as may be prescribed by the State Government and shall form part of the record:
    Provided that, if the competent authority is prevented from making such memorandum, he shall record the reason of his inability to do so and shall cause such memorandum to be made in writing from his dictation and shall sign the same, and such memorandum shall form part of the record:
    Provided further that the evidence of any medical witness shall be taken down as nearly as may be word for word.