Im not sure I understand Piotr, sorry.
What you have written above is a little unclear, but sounds like it should work ok.
The trigger in your screenshot is perfect...
if Count=1 when that slide is first loaded, then the variable RESPOND1 will be set to whatever value the variable AI_RESPONSE holds at that time.
That sounds fine.
And the client request to clear both variables needs just two triggers:
ADJUST VARIABLE "Respond1" TO VALUE <blank> WHEN USER CLICKS "clear button"
ADJUST VARIABLE "AI_Response" TO VALUE <blank> WHEN USER CLICKS "clear button"