Not Another Alternator Q!!!

[obsolete]

So my car has been sitting in the cold for a few winter months and, sure enough, couldn't get it started. It would crank, start clicking, and just die. I was able to jump the car and the voltage on my timer was showing 14.3 or so. I was driving/idling for almost 2 hrs before I was able to get a sears tech to take a look at it and when they did the load test on the battery, it would drop to around 8 volts. So I got the bad battery replaced with a new one. Then they tell me that my alternator failed and I would have to get it replaced. When I was driving home, the volt read 13.7 all the way.

Hopefully you guys could school me, but if my alternator was dead, wouldn't the car die again after i've jumped it? All my lights, dash, electronics were fine and the car ran w/out any problems. Anyone know the likelyhood of an alternator test being wrong or inaccurate? The battery light didn't even come on. I replaced the alternator not too long ago with a used one. The brake light is lit though and will not go away, but I think that might be from fluid level.