David Cartwright says that "Smiley was always coming back from redundancy". Smiley was never made redundant.
Ho says he put trackers on all his colleagues' cars, just in case, a year ago. It seems out of character because then he would have to spend a lot of time to change or recharge the tracker batteries on a regular basis, time he could spend in much greater comfort sitting in front of his screens munching nachos and doing other, more immediately gratifying things.