Is what I did considered an injustice to the servant, even though I did not intend to cause harm, and will God defend him and exact retribution from me?

Among Allah's favors upon His servants is that He does not hold them accountable for mistakes. He answered the supplication of the believers: "Our Lord, do not take us to task if we forget or make a mistake." And Allah Almighty said: "And there is no blame upon you for that in which you have erred, but [only for] what your hearts intended." He has overlooked for this Ummah mistakes, forgetfulness, and that which they are compelled to do. Therefore, you are not to be held accountable for what you did unintentionally. However, you must apologize to whoever you caused harm. If your mistake resulted in damage, you must compensate for it, as intentional and unintentional damage are equal. Whoever damages something owes its value or its equivalent, whether intentionally or by mistake.