I watched it, everyone played well except for dontcryman.
Wrong build
Wrong early itemization
Not too good on early mana management
My opinions on Dontcryman's main mistakes
1) Should have gone coven 1 1st instead of mist, this is the choice for either Reg or Sedna, and he was facing both.
6 crawlers are good for taking out monks and harassing DGs with not so great AA vs multiple targets.
2) Should have gone Unbreakable + Scaled Helm 1st, that extra 600 life points always makes a big difference in overpowering the less beefy DGs in lane.
3) Not calculating his mana, couple of times he swarmed, only to be out of mana which did nothing but put himself in danger.
4) Not thinking ahead vs Dark Crimson Vial.... got to think your enemy has 33% more life then they really do, alot of times he got into confrontations that looked like he was winning, only to have the tables turned.
I know it easy to be critical in hindsight (and I am by no means a godlike player when it comes to mistakes that are easily avoided in hindsight) but you can't be losing in lane to Reg like that unless you are doing something wrong, and if he followed the above advice it would have made a difference. I say these things not to be mean, but to give some ideas on what I think would make dontcry a better player when facing this situation again.
As for things that were out of normal interesting in this game
1) LOL early dark crimson vial on Reg was a pretty neat trick to run UB out of mana early. (but is a bad idea in the big picture with reg's lower then normal late game life)
2) Reg's build was one of my old favorites (1 snipe/range/mines) compared to the gold standard. (Snipe/Mine/WoH)
Things that you should understand in game and apply to most other games
OMG-IN1s itemization/build synergy vs UB
InnerGrace1 + Boots of Speed = 6.9 speed
UB is not going to get that high until later (6.3 base, +.6 with 3 points in Inner Beast)
This puts sednas life potential down, but because it is vs a DOT type of damage, she can run, heal up and return to battle after taking heavy damage, making the enemy UB waste mana and eventually have to yield the lane.