A Maintenance Controller describes his efforts to correct an improper deferral he had made for a broken bonding wire on a B737 Nose Landing Gear (NLG) door that was challenged by an outbound Captain. After the aircraft had departed; another Maintenance Controller informed him the deferral was wrong.

Narrative

Company B737 was due to depart ZZZ when the pilot reported to Maintenance Control that the Nose Landing Gear (NLG) door bonding wire (1 of 2 per [NLG] door); Illustrated Parts Catalog (IPC) Reference 32-22-11; Item # 20; was broken-off and written in the Logbook. It's hard to recall the exact time of the occurrence; but I believe it was right at; or after shift change and as always; the phone lines were lit up and calls were backed up.There were two Technicians on shift at the time. I deferred the item for time with a recurrent check per Maintenance Procedures Manual (MPM) Chapter 53-03-15 using the Standard Wiring Procedures Manual (SWPM) 20-20-00 as a deferral source. The Captain clearly objected to this action and stated I was wrong; including a statement that on a previous aircraft with the same issue; Maintenance replaced the bonding wire. I disagreed with the Captain and faxed him the reference and the aircraft departed for ZZZ1 with no further objection. At this point the whole situation was professional and I don't remember either party becoming or acting confrontational.After things settled down; my peer asked me how I handled the bonding wire and when I told him; he also stated I was wrong. Within minutes of this conversation a Maintenance Control Quality Assurance person; who reviews all new deferrals with recurrent maintenance inspections; approached me with the same concern. I immediately re-read the SWPM reference and realized that I had mis-read the deferral statement. I had thought it stated the remaining bonding wires had to meet the minimum deferral limits and as there are two wires per door; then one could be broken as long as the other met the limitations. As I stated the aircraft had departed ZZZ for ZZZ1 at which point I felt the individual bonding wire was not a safety of flight issue and allowed the flight to continue to ZZZ1. I immediately contacted ZZZ1 Maintenance and requested Maintenance replace the bonding wire before further flight. I then called the Operations Dispatcher and requested he have the Captain call me when he arrived in ZZZ1.I did not hear from the Captain for a couple days; but when he called I explained my actions and apologized for the situation I placed him and his crew in. I was adamant this would not happen again and that I made a series of mistakes; first I went from memory; second when challenged by the Captain; I read the reference and mis-interpreted what was written. I could make excuses but in all honesty I was wrong; I made a mistake and I thought my immediate actions to not only correct the mistake; but yet contact the Captain and apologize for the action were adequate enough for a Corrective Action (C/A). I am very active in everything I interact with in my job. I don't take anything lightly; but in this case I dropped the ball and made a mistake. No one feels worse than I do; however I felt my Corrective Action was professional and adequate to rectify the mistake. The Captain informed me he filed a report and I accepted his reasoning behind his filing of the report.The event occurred because I worked initially from memory because we were very busy with multiple problems going on. When the Captain challenged my deferral; I mis-read the deferral reference and faxed the paperwork to the Captain. I know better than to the let the workload affect my decisions especially going from memory. I should have taken the time to carefully read the deferral reference or query my peers for assistance. This was a big lesson learned; which has changed my whole approach to job accomplishment. I now make sure I review all materials for deferrals carefully and I do not quote from memory in deferring issues with flight crews or Maintenance. I have taken this mistake seriously and now take everything I do one call at a time. I strive daily to ensure this mistake does not happen again. I have apologized to the pilot and I apologize to the company and any individuals who feel my actions were mis-leading; inappropriate or careless; that was not my intention.