The replay camera can be moved to any player, umpire, stumps and a few other locations. The stumps have a wider field of view (FOV) as it does on the telly
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DRS is instituted as it should be.
The batsman will know he has edged the ball as the controller vibrates (he will know he could be out on appeal).
The umpire (game) knows what has happened, however like in real cricket LBW is on appeal only.
It's hard to explain but the best analogous game I can think of is tennis where the technology actually makes umpires redundant as the correct call is known, however they still have umpires and a three challenge rule that has added a new dimension to the game and become a big strategic part of tight matches.