Is Armored (BX) cable considered to be protected from damage?
Based on NEC 320.12(1), I'd say no.

National Electrical Code 2014
Chapter 3 Wiring Methods and Materials
Article 320 Armored Cable: Type AC
320.12 Uses Not Permitted. Type AC cable shall not be used as follows:
(1) Where subject to physical damage

There have been proposals to change it to say &quot;Where subject to excessive physical damage&quot;, and other such wording to show that it offers better protection than say NM cable. So far, however, all such proposals have been shot down.