No I didn't. But in fact the gap between ImmD being notified by my old employer that I have been made redundant and them getting the application from me for my new employment was probably only 1-2 weeks, so it may just have been a matter of timing.
But when I saw the redundancy coming I did phone ImmD and the person I spoke to did tell me that I could stay up until the end of my existing visa provided that I was actively looking to stay in HK. This advice was given without him having my specific details in front of him - just my statement that I was in quite a senior position and that it might take me several weeks or even months to find a new role.