The Pfister involution conjecture in characteristic two

Let $(A,\sigma)$ be a central simple algebra of degree $2^n$ with orthogonal involution over a field $F$ of characteristic two. Suppose that $\sigma$ is anisotropic. The involution $\sigma$ is anisotropic when it is not isotropic, and $(A,\sigma)$ is totally decomposable when it decomposes as a tensor product of quaternion algebras with involution. A field extension $K/F$ is a splitting field of $A$ when $A_K$ is split, and an involution is metabolic when it satisfies the usual metabolicity condition. A bilinear Pfister form is a bilinear form obtained as a tensor product of binary bilinear forms of Pfister type. Then the following statements are equivalent:

Pfister involution conjecture.

1. $(A,\sigma)$ is totally decomposable.
2. For every splitting field $K$ of $A$, $(A,\sigma)_K$ is adjoint to a bilinear Pfister form.
3. For every field extension $L/F$, $(A,\sigma)_L$ is either anisotropic or metabolic.

This characteristic-two analogue replaces hyperbolicity by metabolicity for orthogonal involutions. The implications $(1)\Rightarrow(2)$ and $(1)\Rightarrow(3)$ were known, while the displayed equivalence was resolved by the cited results; in particular, the previously open reverse implications are no longer conjectural.