I agree with you that behaviorism and PCT are different, which is why I don't understand why you're interpreting the robot as PCT and not behaviorist. From the program, it seems pretty clearly (STIMULUS: see blue -> RESPONSE: fire laser) to me.

Well, your robot example was an intuition pump constructed so as to be as close as possible to stimulus-response nature. If you consider something only slightly more complicated the distinction may become clearer: a room thermostat. Physically ripped out of its context, you can see it as a stimulus-response device. Temperature at sensor goes above threshold --> close a switch, temperature falls below threshold --> open the switch. You can set the temperature of the sensor to anything you like, and observe the resulting behaviour of the switch. Pure S-R.

In context, though, the thermostat has the effect of keeping the room temperature constant. You can no longer set the temperature of the sensor to anything you like. Put a candle near it, and the temperature of the rest of the room will fall while the sensor remains at a constant temperature. Use a strong enough heat source or cold source, and you will be able to overwhelm the control system's efforts to maintain a constant temperature, but this fails to tell you anything about how the control system works normally. Do the analogous thing to a living organism and you either kill it or put it under such stress that whatever you observe is unlikely to tell you much about its normal operation -- and biology and psychology should be about how organisms work, not how they fail under torture.

Did you know that lab rats are normally starved until they have lost 20% of their free-feeding weight, before using them in behavioural experiments?

Here's a general block diagram of a control system. The controller is the part above the dotted line and its environment the part below (what would be called the plant in an industrial context). R = reference, P = perception, O = output, D = disturbance (everything in the environment besides O that affects the perception). I have deliberately drawn this to look symmetrical, but the contents of those two boxes makes its functioning asymmetrical. P remains close to R, but O and D need have no visible relationship at all.

 R |
|
V
+-------+
| |
+--->| |----+
| | | |
^ +-------+ v
| |
....... P | ............... | O .......
| |
^ +-------+ v
| | | |
+----| |<---+
| |
+-------+
^
|
D |

When you are dealing with a living organism, R is somewhere inside it. You probably cannot measure it even if you know it exist. (E.g. just what and where, physically, is the set point for deep body temperature in a mammal? Not an easy question to answer.) You may or may not know what P is -- what the organism is actually sensing. It is important to realise that when you perform an experiment on an animal, you have no way of setting P. All you can do is create a disturbance D that may influence P. D, from a behavioural point of view, is the "stimulus" and O, the creature's action on its environment, is the "response". the behaviourist description of the situation is this:

 +-------+
D | | O
----->| |----->
| |
+-------+

This is simply wrong. The system does not work like that and cannot be understood like that. It may look as if D causes O, but that is like thinking that a candle put in a certain place chills the room, a fact that will seem mysterious and paradoxical when you do not know that the thermostat is present, and will only be explained by discovering the actual mechanism, discarding the second diagram in favour of the first. No amount of data collection will help until one has made that change. This is why correlations are so lamentably low in psychological experiments.

Do you have GChat or any kind of instant messenger?

No, I've never used any of those systems. I prefer a medium in which I can take my time to work out exactly what I want to say.