It is certainly possible that the City of Los Angeles has changed back and now al-flex used as a ground path to 6' or less. I'll check it out and post what I find. Most commercial jobs used steel flex anyway, but not all.
On the NEC issue - there is no law stating a municipality or building department must use the NEC as a standard. Many years ago Los Angeles used to publish their own electrical code from scratch. In the 70's or so (I think), they decided to go with the NEC, but then also published a supplement which spelled out their deviations from the NEC. I think they still do this.
After some testing, they determined AL-Flex was suitable as a ground path in lengths up to 100' for 1/2" size. And yes, it had to be squarely cut.
Some other cities and local building departments adopted the standard set by Los Angeles, and some did not. So, if you wanted to use AL-Flex, you had to check with the local building authority to determine if it were allowed as a grounding path or not.
I know of some cases where electricians have had to go back and install grounding wires in otherwise completed work because they did not check, but assumed.
Radar
