when you drop capacity the system will need to rebalance to the new level, it well could be super heated vapour that had been carried along to the point the capacity is droped, then it can flash feeding off the energy stored in the super heated bubbles to level off to a net 0 tempriture gain or loss.

Now here we need to factor in laminar flow as well, the pipe will have closer to ambient fluid along the inside surface as the sub cooled liquid rushes by it with fairly low levels of interaction if no turbulance is disrupting this boundry layer (This is why an olval pipe condencer can out perform a conventional surpentine one of 3 times the size!)

So on the reduced capacity it will consume any internal heat to flash off resulting in a net 0 tempriture change, these where the bubbles you saw, the reason is the condensor has less heat it needs to reject dropping head pressure by a bit. the reason the guages didn't see this is 1 digital guages are slow, 2 laminal flow and a boundry layer acts as a buffer between the fluid streams distorting the real world temp of the fluid refrigerent. so you are correct, there may been no superheated bubbles in this case rather the system simply rebalancing its self. sadly the guages are useles to me as even though I'm in Canada we still learn in imperial!

to see the fluid temp accuretly you need a tool from ritchie that you can put the therm in physical contact with the fluid stream. this will cuas turbulance and break up boundry layers as well as measur the core of the fluid stream yeilding a truer messure of the temp.

now I think I just confused my self, what is the question being posed here again?