Countersteering can mean a few things. Technically (I'm taking this from the motorcycle world) it's the act of initiating the turn. It won't do very much regarding traction during a turn, but it will allow you to "set" into your turn arc much quicker if you counter steer intentionally.
The debate of leaning body more/less than bike will be eternal. I think the reality is that pretty much everyone leans a touch more than their bikes, but their sensation is that they are leaning the same as their bikes. I used to think I never lean more than the bike, except in exceptions listed below, but pictures don't lie - I lean a touch more than the bike. But this is not intentional.
I've never felt comfortable leaning my body more than my bike unless there were extenuating circumstances, i.e. loose or low traction surface with knobby tires (mtb - leaning the bike relative to the ground is terminal more often than not). I lean my body less than my bike when a different situation pops its head up - I need to quickly maneuver my bike around something that is on the ground - like a crashing bike rider, his/her bike, or maybe a little animal. This latter example is true only because your body's weight is so much higher than you bike's weight that it's difficult to move your body around that quickly.
However, leaning the body the same as the bike gives you a lot of stability, not because you're leaning more or less, but because your body doesn't have to do any extra work to hold yourself up. You're relaxed, you can absorb bumps, etc. At cycling's low speeds (under 50 mph), low weight (bike adds what, like 20 lbs to the equation?), the amount of body lean is not really an issue unless the rider exaggerates it one way or another and therefore upsets his/her overall balance.
If I were to guess what happened in that turn where the OP fell, I'd guess the following:
1. OP entered turn really, really hot, just like the other two guys.
2. OP didn't have the confidence to make the turn.
3. OP did one of a couple things in reaction to #2 -
- unconsciously push back on the bars to push body back
- unconsciously feather a brake
- unconsciously move out a bit to reduce cornering arc, then moved back in
3A. OP might have made a simple error.
- run over something in the road which the first two riders studiously or luckily avoided
- drop of sweat fell under front tire, causing it to exceed limit of traction
- someone yelled "YEAH YOU GOT IT BABY" in OP's ear, causing him to flinch a bit
- etc
4. Something from #3 (even something I didn't list) causes front tire to exceed limit of traction.
This by no means is a diss on the OP. I list those reasons because that's what I do when I get scared in a corner, and I've gotten unconscious habits pointed out to me by experts.
Pushing back your body is a natural reaction to diving into a turn too fast but it's the wrong one. I fight this even now (fear is great at stopping the thinking process). I did this just a couple weeks ago at the track. But unweighting your front wheel is the worst thing you can do if you go into a turn hot.
Feathering a brake is also a natural reaction if nervous about going into a corner hot. I did a short autocross type thing with a pro driver sitting in the passenger seat. His comment after I drove? Well, other than something along the lines of "you must like driving fast". He pointed out that whenever I braked hard I'd push the clutch in a bit. I had no idea, so now I consciously put my foot on the dead pedal when braking. I only move it when I feel like I'll need to shift. I never knew I did this but I imagine I've been doing it since I learned how to drive a stick (15 years old) or I learned how to heel/toe (17-21). Either way it was a shock to have someone point it out.
Doing a stutter turn (I don't know what it's called in real) where you move out a bit and move back in, is not good if you're already at your limits. I work on cornering smoothly, i.e. not changing my arc. This is in my car and on my bike, and it is all the time. Changing your arc in a steady turn will only stress your tires a bit more, and if you're at the limit, something will give. Usually it's traction in the front tire/s. (In the car throttle is also important, ditto brakes, and those have other effects, but you get the idea).
Lastly, f you just touched something that the other two riders either noticed&avoided or didn't-notice&were-lucky, that'll push your tire over the limit right away. I think this one is obvious.
No matter what, if you reduce the traction on the front wheel (unweight it or change the coefficient of friction between it and the ground) and you're at the limit, the tire can slip. If it slips, you will probably go down.
Anyway, that's my take on things. There are some things that should be a given when cornering, as some of the others have pointed out.
- corner on the drops to weight front tire more (you mentioned this too)
- unless you have really long chainstays or really high rear tire pressure, scoot forward on the saddle (to weight front tire more)
- check tire pressure (you are aware of this - 95 sounds a bit light for a tubed clincher - how much do you weigh?). Too low and too high and you'll lose traction, but in the dry, if it's pressure related, the culprit is almost always too low pressure.
- look ahead, even if it's by a bit. If you're right on someone's wheel, look up to their front wheel. I get fixated on cogs and that's not good. This avoids mid turn corrections, the "stutter turn".
Finally, if possible, revisit the corner, on foot. Walk around, look at the cracks and crevices and dips and such. You may find something significant. In the Hartford Crit there is an "invisible" dip in the last turn. In the dry no one notices it. In the wet people almost always crash on it, usually when they're going really hot (i.e. last lap). The first year I raced it I went back to the turn to see wtf was in that turn that I couldn't see. I found the dip, realized I couldn't see it while riding (it's a very shallow dip), and made a note of it. When it rains I go way inside or way outside, and doing the latter I've ridden around last lap stack ups to place in the race.
Also, in case you haven't read the thing on road rash:
http://sprinterdellacasa.blogspot.co...rash-care.html
Hope this helps, heal fast,
cdr