A timeline might help here
Create a new timeline and keep it as a separate object if you're using other timelines already (this will prevent future issues).
Set the first period (eg "Main") to -1 duration, making it run indefinitely
Set the second period (eg "Timeout") to however long you want the delay to be, eg. 2 seconds.
When your trigger event starts (eg. arrow hits = 15) end the first period ("Main")
Set the layout to change/end when the timeout period ends
Make a function "end layout" using the function object
When arrow hits = 15, call function after delay of eg. 2000ms