From the top:
Do you think he had TCAS RA?
Probably. Difficult to be certain as the numbers you give are close to the edge of the vertical threshold. If you were both in exactly level flight, then yes. But a slight climb on your part or descent on his would have nudged you outside the threshold. So, how accurately were you both flying?
(perfect I'm sure).
However, it would almost certainly have been a preventative RA directing him not to climb, so maintaining 2,000' would have been in compliance
(corrective threshold at low level is 300' predicted vertical separation at CPA. Preventative threshold 600')
Adopted dogma post Ueberlingen. There are in fact a number of circumstances in which following the RA is not the safest option. This topic debated at length over the last decade (see tech log, search for my user id). Contrary to common misconception TCAS does not fully pretect the flight envelope in most installations and therefore your primary task is, as ever, to protect the flight envelope. Within those constraints the RA should be followed.
Your comments on visual spotting are ... spot on
There is an operational floor to TCAS, believe it is 1000 feet
Yes, various inhibitions kick in at various radio altitudes
but an RA will not command him to penetrate that floor (terrain over plane).
Depends. If there is an EGPWS in the mix, and if it's position is accurate and if it's database correct then you should be safe. However you'll notice a lot of if's in that statement. If your EGPWS is degraded back to basic GPWS it is entirely possible for an RA to put you in terrain.
Not responding to a RA kills people
Again, a very commonly held misconception. The facts are: not complying with an RA introduces a risk. I don't have the figures to hand but IIRC its around 2%. This is of course extremely serious but its a long way from certainty.
What adds massively to the risk is if either aircraft manouvres in the reverse sense. Then the risk skyrockets upto about (iirc) 60%.
The problem at Ueberlingen was not a failure to comply with an RA, it is that the Tupolev crew manoeuvred in the opposite sense
to their RAs, not just once but twice. They descended when being RAed to climb, and they then increased their descent rate when told to increase their climb rate.
Not that I'm not saying it is ok to disregard RAs. But what I am saying is that as professional pilots we have an obligation to understand the relative risks associated with manouevres.
If you want to survive a TCAS incident here is what you do:
1. First and foremost - never
manoeuvre in the opposite sense to an RA.
2. If you get an RA follow it if you possibly can.
3. if you can't follow it get as close as you can.
No - you only get a RA when the other guy also has TCAS. He may have received a TA "Traffic - Traffic".
Incorrect. To be able to generate an RA, TCAS needs the intruder to have an ICAO compliant transponder that has encoded altitude data (i.e. mode C with the altitude reporting turned on.
The only thing you need the intruder to have TCAS for is for the RA to be coordinated.
Everyone else: Items covered above.