Root Canal, was it necsessary?

[Jethro]

Back in April 2016 my dentist did a root canal to number LL1 (one of my lower front teeth), even though there was nothing wrong with it. The reason for the root canal was to alleviate many years of intermittent and very mild radial pain in LL3 that sometimes travelled along and towards the back of my lower jaw. The rooted tooth LL1 is sited three teeth away from the one one causing the trouble, which is LL3 and the dentist had a hunch that it was LL1 causing the ache because it was the only one nearby with a very small filling. However the root was not successful and is now causing far more constant pain than the tooth my dentist was trying to cure. Because I am an NHS patient I have been waiting a very long time just for an appointment to see a dentist in the Birmingham Dental Hospital.
Due to its distant location from the troublesome tooth, is it likely that the rooted tooth was the cause of mild intermittent ache, or was the root unnecsessary.