I have had a look at various dictionaries and have yet to see the word "rumble" as used in the sense of "being discovered" having a separate etymology to the standard word.
I was struck by this from a quick read through an extract from "The Canting Academy" from 1674 ( a dictionary of the Thieves' Cant) and noticed the word "Rumboyle" was Cant for a Ward or Watch(man). This was followed later by the following:
"Romboyl’d Sought after with a Warrant"
This encapsulates the meaning of the slang word "rumble" as in "You've been rumbled, mate." familiar to anyone brought up on the Sweeney. (Itself from a later version of Cant, Cockney Rhyming Slang: Sweeney, Sweeney Todd, Flying Squad. Would you Adam an' Eve it?). There does not appear to be a rhyming element in cant, as the "rum" part seems to recur with a meaning of "well-to-do" or similar.
To me this would mean that this usage of the word rumble deserves its own dictionary entry with a separate etymology. I tried going onto the OED to see if they have this etymology but balked at paying for the privilege.