Tire Blew - Sounded like car backfiring LOUD

So, my biking buddy and I skipped work trying to get some decent mileage in. Had hoped for about 75 as we're training for the Hilly Hundred in Indiana in six weeks. Riding time has decreased since school and soccer has started back up.

Our LBS had a tire maintenance clinic Wed and we went back to her house to practice after. We must have pinched or kinked the tube while changing it out as when we started to ride yesterday, there was a weird noise coming from that tire. We stopped and flipped the bike over but it wasn't rubbing and there were no visible signs anything was wrong. (our list of things to check for are relatively short as we're incredibly new to this sport). About fifteen miles in, it goes super wobbly and BAM as loud as a backfire goes. She managed to stay upright although her rear tire went sliding one way as the 100+ of air went the other.

No levers were needed to get tire off as the adrenaline was pumping and she She-Rah's the tire off. There's a 3 inch linear split in near the valvestem. We put the new tube in and pumped it up with our mini pump. (we have C02 on the shopping list). Rode to the next town which had a BS and aired it the rest of the way up. Ride great now with no little annoying noises so we must have done it right this time.

Question - how do you know if it's been kinked or pinched if you don't see it happen at the time? We'd hate to think of that happing speeding down a hill. Yikes!

hmmm, the way I was taught to change a tube involved a step that makes sure the tube and tire are properly seated...hard to describe-better seen.

The earlier sound and blowout don't go together, a sound would indicate a slow leak-which she likely would have felt over a few miles, a blowout like that is very sudden-no warning noise/signs. I had one recently, there was a nice big hole in my tire which the tube blew through-at the time I was doing 20, 2 feet from a logging truck doing 50-that was scary, not a fan of blowouts!

The length of the split is also odd, any chance there's a rim tape issue (or lack thereof)?

I can't help you much with the weird noise or the blow out but I can with changing a tube:
once you get the the tire on but before you inflate, roll the tire on the rim as if you were going to take it off (but don't remove the tire). This will make sure the tube isn't pinched between the tire and the rim. You'll be able to see if it is when you roll the tire and can free it at that time.

One thing I learned the hard way, don't tighten the nut on the valvestem until AFTER you do the inflating, it can cause the tube to pinch and pop :D

That is the only "flat" I have had so far, I was changing tires and put the same tube back in. oh wait, B/F was changing the tire for me I was watching :p He still can't make himself put 100# in the tires, I have to put more in them after he is done.