When several grantees claim under the same grant, each may answer separately, denying the allegations in the complaint, or pleading performance of the conditions of the grant or asserting any equitable reason why the grant should not be forfeited. Issues of fact shall be tried by jury, and the jury may return a general or special verdict, except that issues raised by any equitable defense shall be determined by the presiding judge. (Amended 1971, No. 185 (Adj. Sess.), § 147, eff. March 29, 1972.)