diff --git a/onchain/script/backtesting/EventReplayer.sol b/onchain/script/backtesting/EventReplayer.sol
index 016770b..3826a66 100644
--- a/onchain/script/backtesting/EventReplayer.sol
+++ b/onchain/script/backtesting/EventReplayer.sol
@@ -386,6 +386,11 @@ contract EventReplayer is IUniswapV3MintCallback, IUniswapV3SwapCallback {
         require(msg.sender == address(pool), "EventReplayer: bad swap callback");
         bool zeroForOne = abi.decode(data, (bool));
         // Pay the positive delta (the input token the pool is owed).
+        // No inline mint is needed here: _replaySwap pre-funds address(this) with
+        // `uint256(amountSpecified) + 1` tokens before calling pool.swap(), so
+        // address(this) already holds sufficient balance.  This differs from
+        // uniswapV3MintCallback, which mints inline because the required amounts
+        // are only known when the pool calls back.
         if (zeroForOne && amount0Delta > 0) {
             token0.transfer(msg.sender, uint256(amount0Delta));
         } else if (!zeroForOne && amount1Delta > 0) {