Because a new jungle TOTALLY affects laning hecarim. And clearly all the items hecarim uses have been completely nerfed/changes to the point of being unviable. That was sarcasm by the way.
The first game I linked he got carried huh.
http://matchhistory.na.leagueoflegends.com/en/#match-details/FRA1TMNT1/400320?gameHash=182c98ae7920eb2e&tab=stats
Let's see, he didn't feed, he had an enormous amount of pressure with strong roams, he had really good initiates, and was able to do a lot of damage for only having a trinity force for damage, all while being extremely hard to kill. That first blood you mentioned? Hecarim was already out csing him before that happened.
So, no, he didn't get carried and it didn't hurt corki. Corki was already doing extremely well (and cop is someone known for always being able to perform well on an even amount of gold). Gold on the guy who is starting team fights is never a bad thing. Because you can do this thing called purchasing defensive items so you don't get blown up instantly.