MSP430F2617: ADC12 over voltage conversion result is not saturated

Part Number:MSP430F2617

I have the following setup:

ADC12 is used with internal 2.5V reference. The input is channel 0 connected to an external pin that can go as high as 5V.

Given that the voltage limit on the external pin as AVCC + 0.3V, this is certainly a problem. However, I would expect that the ADC returns 0xFFF (full scale).

Instead, I read back a low value such as 130, for example.

Is this a known artifact? I could not find it in the errata. I would just like to know if it is possible that the ADC not return fulls scale when the specified range is violated as described.

Thanks!