Now that i have analyzed the time at where the selling started at different exchanges (huobi, finex, stamp), it is obviously coordinated. No way that random people start to sell on 3 major exchanges at the very same 1-3 minute time frame (21:12 UTC, on a Sunday evening, riiight). Organized dump, nothing to see here.
They probably been preparing for this for hours/days. (You need to load up btc on different exchanges, than start selling at the very same time on those exchanges, for an obvious loss i might add - i would just use an OCT service for unload large amount of btc, less hassle, better price - clear manipulation.)
You are describing too much in absolutes. There is a decent possibility that you could be correct; however, what you assert is not obviously the case. There are also concepts described as leading, signaling and following. Sure, there could be some coins on each exchange that are controlled by the same folks or entities, but that is not a necessary factor in order to achieve a similar result with folks with similar agendas following the signal within minutes (as you say) of the occurrence of the dumping on the other exchanges.
You even are bold enough to characterize the dump as "unsuccessful", but what the fuck do you know about the goals and objective of the various players? You are purely speculating because you do not indicate that you know any of them personally (and you surely would indicate if you actually knew any of them, if you did). Let's say hypothetically, one of the dumping entities had some kind of contract with a miner or some other holder of coins that they could purchase up to a certain quantity of coins from them off line (over the counter) (let's say up to 30k of coins) within a certain window time-period based on the BTC price at that time. They may have manipulated prices on the exchanges with a far smaller quantity of coins in order to obtain those coins over the counter (and off the exchanges).
I guess my point is that you don't really know what is going on, even though frame the situation in kind of absolutes and in order to strongly assert that the only possibility is what you describe, which is misleading, and approaching nonsense to describe the situation in such absolute terms.