What is the ruling on someone who performs tawarruk in the first tashahhud then remembers and returns to the normal sitting posture? Is sujood as-sahw (prostration of forgetfulness) required for this, and is their prayer invalidated if they do not prostrate? And what is the ruling on someone who recites aloud in a place where quiet recitation is required, then remembers during the recitation? Do they repeat the recitation quietly, is sujood as-sahw required for this, and is their prayer invalidated if they do not prostrate?

Summary of the Fatwa (definition):

The fatwa stated that the Maliki madhhab (definition) for sitting during the two tashahhud (definition) recitations and between the two prostrations is the tawarruk posture. There is no need for sujud (definition) as-sahw (prostration of forgetfulness) for changing the sitting posture from tawarruk to another posture. As for someone who remembers during recitation that they are reciting silently where it should be audible, or audibly where it should be silent, if they remember before bending for ruku' (bowing), they should repeat the recitation as it should be and perform sujud as-sahw after the taslim (definition). If they do not remember until after bending, they should continue and perform sujud as-sahw before the taslim in the case of reciting silently where it should be audible, and after the taslim in the case of reciting audibly where it should be silent. If they do not perform sujud as-sahw in either case, their prayer is not invalidated. The madhhab of many scholars is that one does not perform sujud as-sahw for reciting audibly where it should be silent, or vice versa.