You are the one who will shoulder all the possible occurence in your trade. But there are times due to the error from the server the broker sometimes compensate trader's losses however it only happens for a few.

Sad to say, you're the one who will shoulder the slippage. Before opening an account, you should read the rules of your broker because of the broker has a 5-10 minutes interval before they gonna execute the orders to avoid paying clients about the orders that does not execute by them in a timely manner.