Fig ale went to 1.004 - reason?

Just bottled a fig ale (recipe I found online: http://www.beersmith.com/Recipes2/recipe_204.htm).

Neighbour has a fig tree which was loaded but the figs were a bit dry for eating (hence not very sweet, which may be part of the end problem).

I brewed and fermented the recipe as is, without the figs, got 1.038 OG. Let it ferment a week at 18c.

Then I skinned and boiled up the figs (idea was to release some sugar), tasted it, not very sweet, strong fig flavour though. So added 400g sugar (which I almost never use, but don't like to drink beers under 4% and the fig contribution to the gravity was an unknown.

After another week or so (going up to 22c) the figs were all white but airlock still chugging.

Took gravity and it was 1.004. Didn't wait to see if it would change, just banged into bottle as quick as I could (after 48 hour cold crash).

First taste, after only a week in the bottle, vaguely reminds me of one my early brews that may have gotten infected or wild yeast (when I perhaps had a scratch in the plastic bucket etc...). i.e. it is just so so dry.

So my question(s).

1. Is it possible for the irish to ferment down this low given what it was working with? (I assumed that there would be some unfermentable sugars in the fruit so did mash lower than I usually do, 65c)

2. or is it more likely that I have infected the beer then I funnelled the fruit into the carboy? (it would have been around 3.5% abv by then though and co2 still actively venting.

I guess if in time I get full on gushers I will know it is #2.

As it happens there is no detectable flavour or aroma of fig so a coopers kit and kilo might be a good comparison to the taste. Who know's it may improve with age.

Any comments would be appreciated. Thanks.