Yes, the board was not designed to withstand 12V input. The input transient suppression diode D7 probably did not protect your board from the overvoltage condition.
VBAT is connected to the PMIC as well as several voltage regulators on the board. Some or all of them may have been damaged as a result of the overvoltage.
You can send it back for repair using the RMA system. (see the website or contact an FAE for details)