So (and this is not excusing her, just observing) I suspect she's gotten into the habit of being to the right of the disc and sometimes steps too far. This appears to be sloppiness as opposed to malicious cheating to get an advantage (like last year's Wysocki/Nikko/McCray incident was). Yes, some will say it's 'cheating' because she's violating the rules and not self-calling, and I'd agree, but I don't think it's 'malicious'.
What the hell is a malicious foot fault?
I still disagree that Wysocki's was intentional. He abbreviated his last stride trying to hit the line mid throw. His last stride is naturally very long... which lead to all of those cart path foot faults. Nikko knew his line would be impossible to hit from the lie and watched and was right. Ricky was probably aware he probably foot-faulted but competitive moment and not wanting or trying to a LOT of doubt can creep into one's head and that small amount of uncertainty is enough to not want to self call.
It is tough and I think in general the sport can survive on self policing but at the highest level it will need officials on each hole or card. The specific issue with foot faults is they seem personal. OB calls and scorecard errors and a lot of other calls can be looked at as a lot more impartial and even summed up as "the disc landed here" where as a foot fault by nature seems more accusatory "YOU foot faulted".
I have a lot more experience at a variety of levels of many different sports. From player, captain, coach, dad, uncle, spectator, volunteer official and paid referee. Having any call that goes against a player be taken as a personal attack is pretty common in so many areas and it is a very difficult thing that some officials develop a very defensive attitude prior to making calls as a result.
I would say in my experiences, no everyone has the mindset to be a good official. Recognizing an infraction and calling it impartially in real time can be a lot harder than it seems it should be. Especially when as pointed out with some of these there is no malicious intent or maybe even the intent was obvious to play within the rules. Ive seen it a bit on vaguely defined OB areas. The amount of gymnastics a card will go through to try and make a throw in bounds can be a bit extreme, and sometimes when it is clearly OB there is can be an almost apologetic nature to the OB call.
As an official in some sports i know I'm bad at it. Why? Because I love watching the sport and become a spectator pretty quickly and real time calls are very difficult. I'm watching for an outcome, i'm watching to see if the disc hits the line I expect or amazed at the flight when a line I don't expect to be thrown is accomplished. staying in the mindset of a referee can be for many of us harder than it seems it should. The other is just flat out sympathy that yes there is not a lot of wiggle room for a call but sometimes it doesn't seem like a huge error and the punishment doesn't
feel like it fits the crime... thats where the interpretation of intent comes in or if they "didn't miss the mark by that much" or tried to hit the mark... big gray area that changes from individual to individual observing and sometimes a stroke seems like a pretty weighty penalty for something that was unintentional and maybe only off by an inch.
Watching swimming I have realized I cannot be a judge. It pains me to watch kids get DQ'd, or worse whole relay teams get DQ'd for many very small infractions, some that area so minor they are hard to see and many don't actually effect the outcome of a race. There is an argument I get, and I understand just like foot faults as JayDub pointed out, it takes focus away from your shot (ie Ricky's concentrating on his unmakable line) and therefore it does create a bigger advantage even if it looks minor or inconsequential when there are others focusing very hard on hitting that lie or keeping their swim stroke legal. It is still, in the moment hard to remember that, letting go of even these small things is wholly unfair to those who work so hard to ensure they are getting it right and play 100% within the rules... and also it isn't personal its simply enforcing the rules of the game.
It would be a big culture shift to get the whole sport up to speed.