The abuser did not show up for the DVRO hearing. Can his/her gun still be taken away?
Yes. California state law says that the ban on guns that is written into the notice that is served upon an abuser when you apply for a DVRO -- the gun ban can apply to ex parte (temporary) orders as well as orders issued after notice and a hearing.1 Therefore, if the abuser was provided with the legal forms that notify him/her of the fact that you applied for the DVRO and that a hearing is scheduled, the gun ban should still apply to him/her.
1 Ann.Cal.Fam.Code §§ 6389(a); 6218