Does the prayer of the one being led become invalid if his knee unintentionally precedes the imam's knee?

The majority of scholars have made it obligatory for the congregant not to precede their Imam. The criterion for precedence is, during standing, the congregant's heel should not be in front of the Imam's heel, and during sitting, it is based on the congregant's posterior.

However, the Malikis hold the view that the prayer is not invalidated by the congregant preceding their Imam.

Therefore, if it is confirmed that the congregant preceded the Imam with their heel during standing, or with their sitting place during sitting, their prayer is not valid according to the majority of scholars, but it is valid according to the Malikis. If such precedence is not confirmed, the original assumption is its absence, and the prayer is valid. Doubt after completing an act of worship does not cause harm, and it is permissible to adopt the view of the Malikis.