Can this cause colic in horses?

When I was turning my horse out tonight I didn't notice that somebody had put sweet feed in his bucket in the run-in, he got to it and ate most of it (I think probably a litre) before I could give him his usual feed (beet pulp and pellets). Could this cause colic? He also was just worked half an hour before but was cooled off enough to have his dinner. I'm just worried because it isn't my barn so I can't go out in the middle of the night to check on him.