What was the date of the first scan, that said you were 7 weeks 1 day? And what estimated due date did they give you from that scan?
Unfortunately for trying to estimate the odds that the first guy is the dad, from what you're saying, viable sperm could have been in your body from both guys when you ovulated. Then it's just a matter of which among the millions of sperm made it to the egg before all the others. It only takes one sperm.
The first guy ejaculating every day, if he never misses a day, could reduce his sperm count. But this can't be sure to make his chances 0%. He probably has lower odds, but not "no chance."
Do both guys know that there is a question and have they both agreed to do a DNA test?
You ask "Does it mean 95% of guy 1's sperm would have been dead by the time I ovulated?" The fast answer is no, but it's really that the question is based on some false notions.
A man ejaculates between 2 and 5 mililiters of semen (on average, about a teaspoon) in one ejaculation. Each ml normally contains about 100 million sperm. This means, one ejaculation puts 200 million to 500 million sperm in your body (and it only takes 1). Even if there were only 5% left, that still would leave 10 to 50 million sperm in your reproductive tract from him. The idea that "most of the sperm would be dead" doesn't help when the remainder is still in the millions.
Also, research is not conclusive about how long sperm stays viable in the woman's reproductive tract. I've seen research papers that give a range of 3-5 days, 4-6 days, and even one that said longer than 7 days (though its ability to penetrate the egg at the 7th day was questioned). So the idea that 95% would be dead based on a five-day time span is not really going to be factual.
Also, you don't know for sure when you ovulated. One doc said the 17th, one said the 16th? but somewhere along the line you were given a due date that (by the conception calculator I use) suggests the 15th.
So, I would take issue with the assumption that 95% of the sperm would be dead, the idea that even if so, 5% of the sperm is somehow not enough to do anything, and the idea that ovulation has been accurately pinpointed to a certain date. The part I do agree with is that the second guy probably put more sperm into you than the first guy, and seems to be a little closer to the date of ovulation. But the first guy is still in range. Is the baby a boy or a girl?