I can't speak for the OP
but abuse does happen among all demographics, it isn't the theory that love is not scarce that is abusive, nor does it have to do with basic poly principles, however there are numerous abuses that take place which are specific to certain sects of polyamory
Once a person is labeled a cowboy or a cowgirl, no matter if it is true or not, is one situation where people justify abusive behavior by rationalizing that they deserve it.
Some polyships, in the name of openess or being able to trust those you are involved with, allow others to have their passwords so that they can read any email of messenger communications, which isn't wrong, but without letting others know by saying "by the way, we share an e-mail account, so just know that I might not be the only one reading our conversation" is not exactly respecting a person's privacy, although that is not black and white in regards to abuse until one begins corresponding with multiple people but under the impression he is messaging one person's private account. Things like changing fonts or variation in the way you end or start a message does not qualify as letting them know they are not corresponding with who they believe they are.
When the person believes they are corresponding with someone they care deeply about, yet their metamour is the one who responds, that is abusive behavior. Even if you don't mind being mislead and honesty and clarity is not important to you, treating others like that without their permission is abusive unless they desire to be treated like that. Since most people -- in general -- don't like being mislead, pretending it was an honesty mistake I would find rather hard to believe.
They way to identify the worst types of abusers is to see how their behavior changes when they believe the cannot get caught -- and therefore will not be held accountable for their actions. Abusers would never abuse others if they were held accountable for their abusive behavior, so they rely to a large degree on subtlety and anonymity, and they will continue to abuse so long as they believe they can get away with it.
I can only speak for myself but if the only reason a person does not commit crimes, is because of a large police presence, I would waste my time with such a person as how are they going to behave the minute the police are gone?
They take advantage of situations as they present themselves which is a red flag to me, I would rather become involved with those who I trust not to abuse another human because it is against their belief system, and not because they won't get caught and certainly not because they simply disagree with another's poly dynamic.
there are many people who would rather poly remain underground and as secretive as possible, because that is the number one way abusers get away with abuse, by keeping secrets that go beyond person privacy
these are just a few of ways abuse happens