I think three important points in this arguement are:
1, scalability of actions. Actions scaled to small levels, for example "I robbed a candy store!" don't impress anyone. Actions scaled to large levels, for example "I personally overthrew the Holder of this planet and now run things" just end up running into the issue discussed here. The middle, however, tends to be good - i.e., you are performing actions large enough to provide bites for others to interact with, but not yet reaching the level where you are claiming, without evidence, to wield large amounts of authority and/or threat.
For instance, I RP'ed Esna as a Holder long before I had any major participation in FW - but, I deliberately never indicated what or where Esna is a Holder of, as I didn't want to be claiming to be the grand poobah of whatever - just a small-scale, newer Holder. IMO (and feel free to disagree, I won't be insulted) this was a good middle ground, as it allowed Esna options in RP to interact with others without claiming authority or influence over a planet or solid assets I don't really have.
2, scale of effect.
Point 1 dealt with how big your supposed action was. This deal with how many people - that is, players - it effects.
The lower limit here is less important - though if it only effects yourself, I don't see the point - but if you claim some action that only has direct pertinance to a single person, you are in much more safe territory than if you claim something that heavily effects a corp of ten, and claim is much safer than something that effects an alliance of one hundred, etc etc..
"But what about personal effects?" you ask. "Does have a small circle of effect allow you to do anything? I think not!"
Of course it doesn't. The reason a small sphere of effect is better is because it's far easier to touch base with all people involved and make sure they're alright with it. Affecting only one person is not an excuse for, to use an actual example I saw, rolling a 'toon pretending to be their ridiculous family member.
3, NPCs and Players in space.
First, I will voice my intense displeasure at the current state of NPC-vs-PC combat in EVE. To my knowledge, NPCs (barring Incursion/Sleeper/officer rats) have not been updated with increased damage/tank/tactics for several years, and in that interim T2 equipment has become omnipresent, faction hulls and equipment far more common, and the commonly-used combat hulls even larger. What this resulted in is a case of "NPC kill inflation". While several years ago cruiser rats were hazardous and BS rats a Big Deal, the numbers killed now make them nothing more than standard mooks while PF is still trying to tell us that 0.0 ratters and L4 mission runners are killing hundreds or thousands of people per rat, maybe tens or hundreds of thousands permission/anomaly.
So yes, anything larger than a cruiser NPC kill is a Big Deal according to PF, but not according to mechanics... and yes, it's a very
situation IMO.
EDIT: KMwhoring, bugged KB ISK values, and other things make Killboard useless as IC measures beyond actually proving you were present and involved in a specific kill.