"Notwithstanding his assessment that the medical certificate obtained by Mr Simmons from Dr Stewart contained ambiguities, the learned Commissioner was in my opinion, entitled to take the view that the certificate was one which gave support to the continuation of weekly payments and was thus a certificate complying with s69(1). He was entitled, in my opinion, to interpret the certificate against the background of the evidence given by Mr Simmons and Mr Hill. Read against this background, the certificate becomes much clearer. Firstly, it should be noted that it purports to be a "progress" rather than a "final" certificate. Secondly, although it certifies that the worker is "fit for normal duties", this must be read in light of what follows viz, that the doctor says Mr Simmons is only "substantially recovered" and, more importantly, that he is to "continue with Kevin Marshall" - Kevin Marshall being his supervisor in the public relations section. It seems to me that the certificate is saying that Mr Simmons is fit for "normal" duties in the sense that work in public relations rather than the cell room was seen to be his "normal" duties. Read in this way the certificate makes sense. If cell room duties are his "normal duties", the certificate makes no sense at all. Once the learned Commissioner made this determination, further evidence as to the actual capacity or incapacity of Mr Simmons for work became irrelevant unless and until a s86(4) application was made."