29.5.3.1 Client Mode Bus Collision
A client receives a read request and begins shifting data out on the SDA line. If a bus collision is detected and the SBCDE bit is set, the BCLxIF bit of the PIR3 register is set. Once a bus collision is detected, the client goes Idle and waits to be addressed again. User software can use the BCLxIF bit to handle a client bus collision.