Hmm, it might be. One way to check could be to print the input event and see if you suddenly get two in a row shortly after each other. Something like this, I think, would help show it:
var time_since_last_event = 0
func _process(delta):
time_since_last_event += delta
# other code here
_on_ClickArea_input_event(event):
if (time_since_last_event > 0.1):
print ("\n")
print (event)
time_since_last_event = 0
else:
print(event)
# other code here
Then you should get output like this:
# if it gets two input events within 0.1 seconds:
[InputEvent]
[InputEvent]
# otherwise, it should look like for each click:
[InputEvent]
[InputEvent]
[InputEvent]
