That sounds familiar. Happened to me on 20 yards last year. No rain in the forecast and a thunderstorm rolled in and sat for 2 hours. I had the plastic on it and as soon as it stopped my dad learned what scrubbing means. we would both scrub a 5 ft strip and then get the broom right on it, it was a rough broom, but matched the day before pretty well and the HO was happy with it. If it was a walkway though I would have hauled it off.We had a parking lot pour that we got placed, floated and finished when the clouds opened up. We put the plastic down but we still lost a lot of finish and had bad plastic marks. It rained for 2 hours. While it was raining we went and got all 7 48" trowels and as soon as it quit we trowel ed the whole thing and broomed behind it. That one should have been lost but we saved the finish on about a 140 yard pour.
Don't ever give up. Never let the concrete win.
That pour is the reason I take a 36" with me on most jobs now. It would have been a 2 hour round trip back home to grab one, I didn't want to risk it.Yeah I'm pretty lazy so I don't like scrubbing and working too hard so we got the trowels out.