Nope, wasn't aware of it on my watch. So I spoke to colleagues still there who've been there nearly 20 years and they don't have any info either. As an aside I haven't heard anything about The Talking Horse in forever, he was such an ass and so despised I'm sure anyone he intervened for would be far worse off!
Thing is, we can both trot out old anecdotes. None of them prove anything. But at least mine are based on direct personal experiences, not third-hand accounts.
When I first arrived I did hear many similar tales where allegedly locals abused their power over expats. For example the rife stories of traffic incidents where blame is placed on the expat unfairly. I say allegedly because in my own experience quite the opposite occurred. I was in a collision from behind while waiting stopped at a red light. The other driver was a young, female, wealthy, traditionally-dressed Emirati (high-end Mercedes coupe, crunched front end). Nightmare scenario for whitey foreigner, right? According to legend I was about to be assigned fault instantly and made to pay for her mistake at best, sent to jail at worst. Everyone "knows" that.
Except, her father showed up in a bit, in full white dishdash, shook my hand and apologized in broken English. Police came, sorted it out, and sent me on my way with the paper to have my car repaired at the other driver's cost. In a week it was repaired (granted my damage was minor) and didn't cost me one fil. Was far more efficient and straightforward than anything I ever experienced in Canada. Truth.
Perhaps I was just lucky. But what I slowly came to realize was that there was virtually always more to the expat "victims" story that they were less forthcoming about. Almost inevitably it would come out from other sources that they had lost their temper in the situation, or been confrontational, verbally abusive or used profanity in the heat of the moment. Big no-no's in that part of the world. Do not show anger, do not raise your voice, do not embarrass them, do not give reason to believe they've lost face. If you do these things it will no longer matter who is "right", it will become who has more wasta and as an expat you WILL have a very bad day. I was calm, polite and respectful with the young driver, her father, and the police and believe me it counts. If having to behave this way offends you, then yes, the ME is probably not the place for you. Things usually end badly there for those with poor impulse control.
In that context I highly suspect there may be a fair bit more to the diversion story than "influential local has pilot thrown in jail for diverting". Given the hundreds of uneventful diversions over the years including a few of my own! Even if it's 100% true it is an absurd outlier and thus hardly a strong way to try and make a point. I reiterate, Dubai jails are not overflowing with innocent expat pilots.
My advice remains, know your environment and adapt accordingly. But I do realize that some minds can never be changed so with that, I shall leave all to their biases to make their own choices!