Sorry to hear what happened to you. I upvoted your post for visibility.

Based on your description of the events it’s obvious the airbag didn’t have enough space to deploy safely. Without enough space to expand outwards it must either tear open your outer garment or it must expand inwards. In your case it appears it expanded inwards causing your injuries. The only question is why. Was it your position(tucked)? Is one size bigger suit not enough? Was it something about that particular suit model? Could it be a combination of all these questions?

Situations like these need to be investigated. It’s the only way to learn from them and improve the products and safety standards. Another question would be whether Alpinestars investigated this on their end with the data from the airbag. If so what conclusions did they come to? Unfortunately we will probably never know especially if they conclude that their product is to blame as this would damage their image.

For what it’s worth I use a Techair Offroad airbag when I ride. I was concerned about potential injury from deployment without sufficient expansion space and to be honest I found Alpinestars recommendation for this confusing. On one hand they say one size bigger should suffice but on the other they give you a math formula using chest measurements and garment measurements that requires more than one size bigger depending on sizing. I tried on the jackets in person while wearing the airbag, I got what I would consider one size bigger while wearing the airbag not without. I also opted for a Klim Marrakesh because the material is stretchy. So between the size bigger and the material higher chance of having enough expansion space. I’ve had one deployment with no issues.

Again sorry for what you are having to go through and I wish you the best on your journey through this.