How Bad is This?

I usually am pretty optimistic when it comes to all this, but I think I may actually have ruined a batch of wine.

We made a plum wine using 8lbs of plums, a few lbs of sugar, campden, pectin enzyme, tannin, etc.

At a week we racked it off of the fruit into glass. Again at a month. It tasted surprisingly good for being so young. Nice color and everything.

We decided to let a friend hide it so we would not be temped to sample any.

When I found it, the airlock was off the rubber stopper.

It is in a gallon carboy with the stopper still inserted. But there was the little hole where air was able to get in for 3 days.

Think it's ruined??

Not likely. Unless there were major pressure/temperature changes in the three days very little got into the jug.

Sounds like maybe your friend sampled a little; so, maybe ask the friend how it tastes?