^^ what he said and also, have you watered them in the past 2 weeks? Its always a good idea to crop/prune the roots after taking that much veg off the top. What I do is position a long knife (long enough to reach bottom of the soil) halfway between the stem and the outer perimeter of the pot, plunge it all the way to the bottom and work it all the way around the pot. this eliminates a good portion of the unnecessary roots. Bottom line, the plants had a fully functional rooting system for "a couple of nugs".
Your lucky you didn't have water squirting out the top.
(I jest)