Feel free to dispute or disbelieve any of what I am about to share but, for the record, I've never met a computer or computer program that I couldn't make my bitch...
First, if the 'glitches' in a major system like Poloniex aren't remedied, it is because it is not in their best interest to do so. A system like theirs cannot be run without people who have the expertise to keep the system fully updated and fully functional. It is highly unlikely that a system like that would be allowed to fall behind in its capabilities 'merely' to avoid cutting into profits, especially since keeping such a system fully functional increases profits much more than the cost of updating/upkeep.
Which leads to the question of not whether the system is being 'gamed' from the inside, but rather, by how much the system is being gamed. ( Quick, name all of the Casinos that have never had some...or even most...of the 'cream' skimmed off the top. Answer: None ) You can bet your bottom dollar that someone between the CEO and the janitor has figured out a way to stash away a nice piece of change from anomalies that are 'negligible' in terms of the whole picture and, more likely, a number of people in the system have figured out a way to nibble off a few of the crumbs 'falling' from the table.
Then, figure in the hackers (both insiders and outsiders) who are well aware of the money to be made in the 'time lags' caused by DoS attacks...similar to the 'telegraph/wire' scam portrayed in the movie 'The Sting.'
I use Bittrex, which is, by and large, able to keep fairly current even during the times of large loads on their system. However, there are occasionally system 'slow-downs' which inevitably come at exactly the time that even a few seconds difference can mean a significant difference in the returns one receives. Anyone who eats, sleeps and dreams computers and programming can tell you that these instances occur because someone is 'making' them happen. Not to mention that I have watched an 'extremely insignificant' amount of my buy/sell orders quite simply disappearing...something I only notice when micromanaging my account. The first few times I 'caught' the...uhh, we'll call it an 'error'...I reported it and it was 'rectified' immediately, which leads me to believe that the 'error' either came from within the system, or the workings of someone from technically 'outside' the system were 'fixable' when found.
After the first couple of 'errors' I no longer bothered reporting them. I'm not going to spend a great deal of time chasing down a few cents...usually less than a nickle.
Do I 'think' that someone is pinching a few of my pennies? No, I know someone is... Do I care? Nope. It really is 'insignificant' and better that someone should put away a decent retirement savings account with few pennies from a lot of people than to go to the trouble to provide 'absolute proof' that it is happening and having people panic and jump out of windows, making my holdings worth a whole lot less, when it really is inconsequential, like leaving a night light on when you go on vacation increasing your electric bill, but not enough for you to come home early.
Trust me, any system that can be 'gamed' will be gamed. And any system can be gamed. However, for the most part, any 'gaming' of the system that is taking place is likely 'losing' you much less money than the 'everyday' workings of the system such as a BitCoin ATM that uses an exchange rate of $ 1,500 when BTC is well over $ 1,800 in value.
The most you can expect is for the companies you are dealing with to have sufficient security and safeguards in place to make sure that Bernie Madoff isn't dipping into your money. Better that the janitor should be picking up a few coins that get dropped on the floor.