Well it didn't take much playtesting for this rule to need adjustment as it does not in the above state prevent the kind of scenario that the Doc pointed out.
Here is the revised rule
"Any character armed with a weapon which is capable of a counter attack may spend 1 VP as his/her action phase to become counterattack ready - CR
CR can be activated whenever any enemy figure enters or moves onto the same path as the figure with the counter. For each circle entered first the defender (the figure with CR) then the attacker can announce an attack. If Either player announces an attack the opposing player can, but is not required to, announce a simultaneous attack.
If the CR decides to fire – there are one of two options
a) use normal combat including modifiers and lose CR status
b) use lowest printed combat value (which can only be modified by on the board status and nothing else ie smoke, certain combat circles etc) and retain CR status
in any case the CR player may only fire at each individual attacker once. The moving player is allowed only one attack as usual."
I'll try this out and report back
Regards
Nhoj