The trinket, like many others, has a 10 second ICD to avoid overlapping. I have not got concrete evidence that this is a fact, but in all the experience I have with it I am confident enough in saying that this is the case.
Personally I think the ICD isn't there to avoid overlapping but more to provide you with a time frame in which to wait before killing yourself when it doesn't proc.
Vendoring this trinket will be the sweetest feeling.