COVID hits the sweet spot of infectiousness, asymptomatic spread, incubation time, and low mortality. I would expect the R of Ebola to be pretty low in developed countries. People wash their hands more often when every place you go to has running water, and if you show Ebola symptoms, you're going to the hospital, and if it's a hospital with a city that has a BSL4 lab, there isn't going to be an outbreak - someone will recognize what it is, and you'll be in an isolation unit in no time and your contacts will be quarantined.

I would expect such a case to make the headlines, but it's quite possible it would be quietly swept under the carpet. How well known was Reston back when it happened? If that didn't make the news, would a lab-originated outbreak?

With COVID, a worker could get infected, hide the exposure out of fear/shame, never show any symptoms... and yet start a pandemic.

With a low-probability high-impact event like a global pandemic, near misses are the only indicator you have until the one time it does go catastrophically wrong.