Hmmmm... the Toshiba disc was 5GB a LAYER and designed for 2 layers and two sides. So because you're wrong I'd say that is FUD.
No. Toshiba's proposal was for single-layer dual side. Just like laserdisc. They called it SD for "super Density Disc"
Dual-layer was Sony's concept.
The DVD forum married the two concepts into the unified DVD format we enjoy today. The spec allows for dual layer and/or dual side. Several early DVDs were indeed "flippers" just as Toshiba's format would have resulted. T2 was the industry's first continuous-play dual-layer disc to follow Sony's concept in full. It's the pattern of virtually every feature-title authored to DVD today.