My camera glitched during the next part, but in order to avoid having kernels that catch in your teeth, and any seeds that were burned by insufficient shaking, I actually grabbed a second pot, and shoveled all the good popcorn into the new pot.
This keeps your trick-or-treaters (or your own) teeth free from annoying corn that takes a while to go away.
Once you have your good corn sorted from the bad, pour in your sugar syrup.
Mix well, with the stove still on.
When you pan holds oil only, all the heat is transfered to the oil. When the popcorn is added, the oil heats the corn so it pops. Once the sugar is added, the corn will not burn (as long as you keep stirring), because the entire mass needs to make it up to equilibrium temperature before any element will get any hotter.
Once the corn is well-coated with the syrup, pull the pan off of the heat.