One of them being a closer than was ideal situation with a cyclist in the dark where I had two vehicle coming up fast behind me one in the other lane and one right behind me who hadn't seen the situation and in the spur of the moment I couldn't not take into account, slightly delaying my reaction, that suddenly braking might have him going into the back of me even though it was a better option than splatting a cyclist (and if the cyclist had been wearing high vis I'd have had an extra ~1 second to make a better decision in).
Had a very similar situation some years ago.
Rural, Unlit DC, Night-time, dreadful weather. (Wipers on fast were only clearing about 2" of screen trialing the wipers. Dipped lights cos of traffic coming other way. and lying water on the road)
Now because of "My Rules" with these conditions I was traveling only between 35-40. No more than that, so when the Cyclist came into view I would normally have had plenty of time to tap on the brakes and follow him untill safe to pass.
Unfortunately, I had no confidance that the HGV 12ft off my back bumper would be able to do the same, and of course, this is the point where another HGV was attempting to pass the both of us...
Now, I don't know how they could see where they were going either but I guess the impact of rain and road spray might be less the higher up you are, also the aerodynamics of a truck cab may be different from that of a smaller vehicle as regards deflecting rain before it even gets on the windscreen.
OTOH, maybe they couldnt see any better than I could but just didn't give a damn **** anyway

(I suspect the latter really)
Anyway, It is amazing what you can think and do in the space of 1-2 seconds.
So, No point in braking at this stage. I could but truck wouldn't. So I would just get pushed into
bloody idiot Cyclist and we would both die.
So, Light tap on brakes, just enough to light them up, Right indicator on (Even one flick of Red and amber might give the following truck driver the idea that something amiss was unfolding)
Blast on the horn (Not a toot, one long continuous blast). Again the truck driver might hear it and the
bloody idiot Cyclist might get the message that the jaws of death are upon him and that his only hope of salvation would be an immediate, no compromise, diversion into the ditch.
And all at the same time pulling over as far as I dared to the overtaking truck and hoping that, at least, I would be able to pass without hitting him.
Moments later, the following truck was still behind me so I concluded that by this time the
bloody idiot Cyclist was either lying in the ditch, even wetter and muddier, but alive. Or a greasy smear in the middle of the road with the truck driver ether not realising he had squashed somebody (easily done in these conditions I would think. I was driving a high top van and he could easily have not seen the cyclist at all with me in his line of sight).
Or knowing that he had done so and not caring!
As it was, over the next couple of days i kept an eye out in the local paper and for those "Fatal Accident" signs that are sometimes put up appealing for witnesses. Nothing transpired so I guess he survived relatively unscathed. (Either that or his rotting corpse is lying wedged in a drain culvert somewhere to this day)
Whether he learned his lesson over when/where is and when is not a good idea to ride a Bike I don't know. But I suspect not.
Anybody who would even have considered riding a bike under these sorts of conditions would already have been too far gone! :/