Nah, J. Marcus is definitely insinuating that cheating is involved. Here are a few snippets from his post on twitter that make his opinion clear:
"Relative to results, I find Nuguse's stride to be very problematic — and I don't think his results should be taken at face value."
"Do SuperShoes fully explain Nuguse's exceptional marks as of late?
I don't think so."
"In addition to shoe tech, there seems to be something else enhancing his performance ability, but I can't say what."
"When hard scientific realties are being violated en route to out-of-this-world performances I think some healthy skepticism is vaild."
"... what NOP/Salazar, Lance, Team Sky etc. has taught me is: sudden, superhuman feats should be provisionally celebrated with a degree of skepticism."