The blowout was almost certainly not caused by a defective tube. Even a defective tube would have simply lost pressure, rapidly or otherwise, without dislodging the tire.
If your rims are hookless, they're more prone to allowing blowoffs than any rim with hooked sides.
A modern tubeless and hookless rim is pictured at right below, but many older bikes, especially those with 27" wheels, had hookless (a.k.a. straight-sided) rims.
