I am not clear why the assertion is made in this scenario that the law enforcement officer did not do his job, or even that he did anything inappropriate. The reason for the bench warrant was that the defendant did not appear for court and the obvious goal of such a warrant would be to cause an arrest that would secure the defendant's appearance in court. If a law enforcement officer is able to secure the defendant's submission to the court in some manner, such as a phone call and the encouragement to surrender, the purpose of the warrant has been carried out and it will be up to the court as to whether to recall the warrant or to take some other action based upon the initial failure to appear.
The prior attorney gave you an excellent answer, the theory is that justice is served and it sounds like that is your goal. good question and i wish you all the best, take care.