This tortoise version of bros before woes took place in Taipei, Taiwan, and according to the translation of the YouTube video description: "Animals have compassion, too - encountering a flipped turtle by chance, the turtle's companion comes to his rescue."
That this tortoise understood his friend needed rescuing is not an implausible idea. Though scientists are still trying to decipher the sounds turtles make, shelled reptiles are certainly capable of social communication. Desert tortoises, for example, let out a variety of noises like hisses and "poinks," which may be distress calls.
And it's not the first time a tortoise has come to his friend's aid, either. (Though this guy takes his sweet, turtle-y time):