How much can Rejuvenation tick heal?

Hello all,
I would like to keep this as simple as possible.
https://www.youtube.com/watch?v=4xHnBBh_z9Y
In this video, at 1:48 you can see her/him casting Rejuvenation r11. It ticks for 520 health. What is bugging me is that it seems way to strong for someone with that gear (earlier in video you can see the gear being shown - pretty much dungeon gear, Pre-MC BiS). You can also see that no special buff or trinket is being used, so that tick gains just the benefit from the gear.
I would like to hear from some experienced druids, or any other healers, whether having 520 rejuvenation ticks with a mostly blue gear is possible? Because from what I heard, 500-500 rejuv per tick is the end-game healing with t3 gear.
Thank you all in advance.
I would like to keep this as simple as possible.
https://www.youtube.com/watch?v=4xHnBBh_z9Y
In this video, at 1:48 you can see her/him casting Rejuvenation r11. It ticks for 520 health. What is bugging me is that it seems way to strong for someone with that gear (earlier in video you can see the gear being shown - pretty much dungeon gear, Pre-MC BiS). You can also see that no special buff or trinket is being used, so that tick gains just the benefit from the gear.
I would like to hear from some experienced druids, or any other healers, whether having 520 rejuvenation ticks with a mostly blue gear is possible? Because from what I heard, 500-500 rejuv per tick is the end-game healing with t3 gear.
Thank you all in advance.