@Oxenos (post 14)
I fear you have missed part of the quote you posted, thus distorting the FAA Advisory Circular, though the guidance is itself contradictory
12.b. Pilot Responsibilities.
The intent of a TCAS is to serve as a backup to visual collision avoidance, application of right-of-way rules, and air traffic separation service. For TCAS to work as designed, immediate and correct crew response to TCAS advisories is essential. Delayed crew response or reluctance of a flightcrew to adjust the aircraft’s flightpath as advised by TCAS due to air traffic control (ATC) clearance provisions, fear of later FAA scrutiny, or other factors could significantly decrease or negate the protection afforded by TCAS. Flightcrews should respond to a TCAS in accordance with the following guidelines when responding to alerts:
(1) Respond to TAs by attempting to establish visual contact with the intruder aircraft
and other aircraft which may be in the vicinity. Coordinate to the degree possible with other crewmembers to assist in searching for traffic. Do not deviate from an assigned clearance based only on TA information. For any traffic acquired visually, continue to maintain safe separation in accordance with current regulations and good operating practices.
(2) When an RA occurs, the PF should respond immediately by directing attention to RA
displays and maneuver as indicated, unless doing so would jeopardize the safe operation of the flight or the flightcrew can ensure separation with the help of definitive visual acquisition of the aircraft causing the RA. By not responding to an RA, the flightcrew effectively takes responsibility for achieving safe separation. In so choosing, consider the following cautions:
(a) The traffic may also be equipped with TCAS and it may maneuver in response to
an RA coordinated with your own TCAS.
(b) The traffic acquired visually may not be the same traffic causing the RA.
(c) Visual perception of the encounter may be misleading. Unless it is unequivocally
clear that the target acquired visually is the one generating the RA and there are no complicating circumstances, the pilot’s instinctive reaction should always be to respond to RAs in the direction and to the degree displayed.
It also goes on to say
(16) The TCAS alone does not ensure safe separation in every case, nor diminish the
pilot’s basic authority and responsibility to ensure safe flight. TCAS does not respond to aircraft which are not transponder-equipped or to aircraft with a transponder failure, and can display erroneous indications when a transponder malfunctions. TCAS RAs may, in some cases, conflict with flightpath requirements due to terrain, such as an obstacle-limited climb segment or an approach to rising terrain. Since the basis for many approved instrument procedures and IFR clearances is avoiding high terrain or obstacles, it is particularly important that pilots maintain situational awareness (SA) and continue to use good operating practices and judgment when following TCAS RAs. Pilots should make frequent outside visual scans while using see-and-avoid techniques. Communication with ATC should be initiated as necessary.