As noted, Hiromu Takahashi suffered a neck injury in his IWGP Jr. Heavyweight Championship match against Dragon Lee at last weekend's G1 Special in San Francisco. After finishing the match, he reportedly collapsed backstage and was taken to the hospital shortly after.
The injury was said to most likely come from the move below.
"On July 7, during the G1 Special in San Francisco event, Hiromu Takahashi sustained a neck injury and was taken to a San Francisco hospital for evaluation.
Takahashi was able to return to Japan today, and will proceed with treatment. We apologize for the delay in publishing this update, which was in order to ensure smooth and efficient transit for Takahashi at the airport. We deeply appreciate our fans' concerns. Please stay tuned to NJPW for further updates."
In his championship match, Takahashi was able to wrestle for another couple minutes after being dropped on his neck. He would eventually hit his finisher (Time Bomb) to pick up a pinfall victory and retain the title. Takahashi is a two-time NJPW Jr. Heavyweight Champion.