infected or contaminated is entirely appropriate if an organism is living in your beer that you never intended to
In the biological sense I do not believe infection is appropriate because it deals with pathogens. In beer nothing is actually getting attacked- it's competition among microorganisms not pathology. I agree contamination is always appropriate when it is unintentional- I would absolutely use either term when applied to mold, mildew or anything really undesirable in your beer.
When it's a drinkable sour, accidental or not I prefer the term wild or spontaneous fermentation because it is far less discouraging to people who may be willing to give it a try if they know it won't hurt them. Even if I sound like a jerk off ATM (I'll go on youtubes if I really need to troll somebody ) I really would like to prevent new and new-ish brewers from dumping a whole batch they might enjoy just because terminology implies there is something wrong with it.
Thankfully a good number of brewers do exactly what the OP did and start a thread just like this one and receive valuable advice which leads them to a successful beer.
Also like to apologize for derailing the end of the thread.... I only recently began liking sours anyway; don't know why I am nitpicking their associated terminology so adamantly. Cheers everybody!