I thought you just flushed? if so, I wouldn't worry. I intentionally over nute. I gradually increase the dose until a minor overdose occurs, then I pull back on the dosage.
A minor overdose appears as the tips of leaves dying and sometimes the sides curling up. You described spots, Thats when your plant is cannibalizing itself for stored nutes. Usually spots mean micronutes while general area necrosis usually indicates a macronute. This is all just in my experience(and what I've read), So just check it out, search for "rust spots" and you'll find the thread with the info you need.