It is standard MO, from what I experienced.  The lawyers will advise their clients to plead not guilty. 

I know cos many years ago, one of the company I worked for exceeded the schedule B effluent (before I joined the company, of course).  As I was also in charge for ESH, it falls under me to attend the court.  Met with the lawyer from a very reputable law firm in KL. the first thing the lawyer told me was don’t admit guilt.  I argued with him that the data showed the effluent exceeded plus my internal investigation showed there are some ‘issues with the flow of waste water form the lines’.  He still insisted no admission on guilt.  Then later, he admitted cannot argue and I attended the SA court.  In the end, kena fine close to 50k… maybe those in the law industry can advise…