This article tries really hard to make this a UFO mystery, but jets fell out of the sky pretty regularly in 1953, especially in storms and at night. Radar technology was also not anywhere near what we have today and even with modern technology we can still just outright lose a plane. MH370 still hasn't been found for example.
(I'm not a radar operator per se but I did study weapons engineering at the NL naval college and spent several years of my military career specifying specs for advanced naval radar systems)
So an intact jet fighter will show up as a big dot, while falling debris might look like many small dots, or be too small for the resolution of the radar display.
There's also numerous sources of interference and background noise, including from weather. So on a stormy night it might not be apparent what is debris vs water.
The article is really more of an advertisement for a TV show than journalism and doesn't give a very clear account, but it sound plausible that two dots converging and disappearing from radar could represent an in-air collision. And if over the great lakes during a storm, investigators would be looking underwater for hundreds of pieces of non-magnetic aluminum spread over many square miles.
From the few firsthand wartime accounts I've read of planes being shot down, from the perspective of radar operators they just abruptly disappear.
Also keep in mind this would have been 1953 tech.