The 365 is normally flown with the coupler on standby (green CPL annunciator on the A/P control panel). Any mode including G/A can then be engaged. But with the standby light out no coupling is available.
A failing attitude indicator can kill, see the NTSB report below:
http://www.ntsb.gov/ntsb/brief.asp?e...12X19083&key=1
Question is: can we adequately simulate and/or train to recognize and react to such a failure?