When you look at the trajectory that this object took through the solar system, coming within .14 AU of earth, you really have to wonder; what are the chances that it was a random flyby?
It just sounds small when you write it as 0.14 because it's a small fraction of an AU, but an AU is freaking huge. If we sent a probe to Jupiter and it only got within 0.14 AU I can't see that being considered much of a success.
~99.9̅% chance of being random. Absent any sort of evidence, it was a rare, meaningless event. The law of large numbers, however, suggests that rare events occur more frequently than you'd expect. E.g 1 in 1000 year floods could occur 3 times in a decade, since each event is statistically independent from others.
Where did you get that number from? Because it looks like you made it up.
In other words the odds that that specific rock get’s that close is low. But, if we only observe rocks close to us then the odds that we will see a rock close to us depends more on the number of rocks than the low odds for anyone rock.
More generally becase we notice unusual events more than common ones you need to consider all possible unusual events you would notice not just the odds of that specific event.