If you add an exchange that has outgoing cryptocurrency withdrawals to your local wallet, but don't add your local wallet, then CoinTracker does not know if the wallet is yours, a friend's, or a merchant's. Therefore, to be conservative, the default assumption is that a non-tracked wallet is not yours and therefore a taxable send event.
If that is incorrect and the transaction should instead be a transfer to a local wallet that you control, then the fix is to simply add your local wallet to CoinTracker (we currently support ADA, BCH, BTC, DASH, DOGE, EOS, ETC [including ERC20 tokens], ETH [including ERC20 tokens], LTC, NEO, QTUM, TRON, XEM, XLM, XRP, XTZ, and ZEC local wallets). If you run into any issues, please see the FAQ about cold wallets.
If the transfer is for a wallet we do not yet support, then you can mark the transaction as a transfer using the down arrow next to the transaction from the Transactions page. Behind the scenes, this simply adds the same amount of coin which was Sent/Received as Received/Sent. You can undo the operation by manually editing the transaction back to its original state.