The whole idea that if you tag someone for something then you have to tag everyone who's done the same thing is one big fallacy.
If you change the timing of both actions to be on the same day, it is not a fallacy.
It still is. It would be ridiculous to expect a DT member to tag every person who's done that "thing", same day, or the day before, or whenever.
If you get a speeding ticket it doesn't mean that the same officer/trooper/deputy needs to ticket all other speeding drivers in the world.
that's a straw man. no one expects that. the OP gave specific examples; there's no need to go digging for every untrustworthy action that has ever been done before.
the question is what happens when a DT member (or someone close to DT members) gets outed for behavior that the community has deemed untrustworthy. if you regularly tag account sellers, but refuse in these cases, it's reasonable to assume there is a conflict. a conflict of interest can be as small as giving one person consideration (or retribution) where they otherwise wouldn't. eg hooking your friends up with the perks and favors from your government position while the public at large gets nothing. that's not the worst thing in the world, but let's just be honest about it. that's the definition of a conflict. that's how positions of authority work. anyone who works in government law or ethics will tell you the same.
that means the cop in your example isn't supposed to get his drinking buddies off the hook when they break the law. or let hot women off with a warning when they're caught speeding while ticketing everyone else. but what do you think actually happens in practice? use your head.
this thread was about conflicts of interest, not pontificating hypothetical situations where it's unreasonable to expect anything from DT members. if the latter is the position we're supposed to take, DT absolutely shouldn't exist.