Is it normal that an endodontist will leave a portion of a curved canal untreated?

[imanein]

4 weeks ago I went for 2 root canal procedures. The first tooth was easy as the canals weren't curved but the second had a curved canal. the doctor did the whole treatment in three sittings , when the procedure was over I asked him if he  faced any problem treating the curved canal to which he responded that a portion of the curved canal was left untreated because its size was bigger than the instrument, something about 18% was not treated. I thought good endodontists try to treat the canal fully no matter how bad the curvature is, is this normal? he also admitted that this could lead to an infection and ultimately the failure of the procedure. I felt like he wasn't even trying, and i had that feeling that he was rushed by the next patient , overall the treatment took 2 hours in total, half an hour each for the first two sittings and 1 hour the day he was sealing it. I feel that he didn't try all other possibilities or was rushed by the next patient. Do you think showing it to another doctor would help? I have not restored the tooth yet cause I am worried.

[scottma]

Seeing another endodontist is advised.