"Stray bombs" are a euphemism. From a great deal of reading and, over the years, talking to RAF, USAAF and Luftwaffe aircrew it is clear that even the most refined 1940s bombsights were never more than 60% accurate.
The bigger the target, the bigger the chance of doing real damage but, if you want to understand just how hard it is to hit and destroy a small, defined and very specific target read the histories of the Amiens raid, the Schwienfurt raids or raids on specific bridges. Consider how the Stockport viaduct was a prime strategic target and how it survived.
When you are above 5,000 feet travelling at over 200 mph with variable wind between you and the target and all you have is 1940s technology plus Mk1 eyeball to find and lock onto your target which is shrouded in darkness, with flak bursting around you and cloud moving across your line of sight, "stray bombs" are a certainty and they destroy or damage what they hit.
There are, of course, many examples of crews totally missing targets (the bombing of Dublin, mistaken for Liverpool is a major example) and crews under attack, or having missed the target and turning for home, would just get rid of their bombs to help increase aircraft performance - often reporting they had hit their target (this happened in all air forces) but, if in 1939-1945 you lived within 3 miles of any target in Europe subjected to high level bombing, you stood a chance of getting hit due to poor target acquisition, misidentification or unsteady approach to target (a one minute straight and level approach at 20,000 ft was the norm if you wanted to stand a chance of hitting what you were supposed to and, I'm told, that minute seemed a lifetime).
My wife's mother lived in Farrant Rd as a teenager throughout the war and that area of Longsight was hit from time to time, especially between winter 1940 and the summer of 1942, though she doesn't recall any major incidents.
She does recall seeing Luftwaffe aircraft machine gunning Birchfields Rd and Moseley Rd whilst she was en route to school at The Hollies.
I wonder why
Margaret’s Blog » World War II (para 2) recalls one particular incident but not what would have been a greater local disaster just a few hundred yards further south.
Talking as I was of misidentification, both Crowcroft Park and Gatling Avenue are in Levenshulme and, to get back to the subject, it is a little strange that, were there to be truth in the story of whole terraces being demolished, neither David Boardman's Longsight pages nor George Nixon's Levenshulme pages have any memories of what would have been a major local incident.