A notice given under section 301 may not be held invalid or insufficient by reason of any inaccuracy in stating any of the facts required for proper notice, unless it is shown that it was the intention to mislead and that the employer was in fact misled by the notice. Want of notice is not a bar to proceedings under this Act if it is shown that the employer or the employer's agent had knowledge of the injury. Any time during which the employee is unable by reason of physical or mental incapacity to give the notice, or fails to do so on account of mistake of fact, may not be included in the computation of proper notice. In case of the death of the employee within that period, there is allowed for giving the notice 3 months after the death.   [PL 2011, c. 647, §17 (AMD).]