I've been playing a lot of Evelynn recently and I noticed that if i stood in a bush beside one of Heimerdinger's turrets I would remain stealthed. However if an enemy walked by me outside of the bush within my detection radius I would be revealed to that enemy, even though I was inside a bush and the enemy was outside of it.

I do not think this was caused by a pink ward

This is currently working as intended. Green wards have the same functionality as heimer turrets.

But you were Eve

Why was Heimerdinger still alive

To expand / explain his comment a bit more for you, Battle Leader:

Pink Wards vs. Eve

• Completely sees through Eve's stealth.
• Standing within range of this shows you to the enemy team.

Heimer's Turrets & Green Wards vs. Eve

• Gives NO vision of Eve if she's stealthed. You are safe.
• These items also provide presence in the bush; EG: Heimer can see inside the bush his turret is active within. This to you seemed like the turret was broken/seeing through your stealth; The contrary is actually true- It had no idea you were there, but since H-Ding could see inside the bush you were in, he broke your stealth.

The main problem with this is no other vision based thing works this way.
Pink ward outside of a bush and your champion is in the bush, you still cannot see in there.
If one champ has oracles out side of the bush, and another champ is in the bush, you still cannot see anything stealthed in the bush.
then there is eve, which is completely counter to this.

Thank you for the responses and explanation .

Are these true? Like, actually?

That isn't the same comparison. Say Shaco has just teleported into the bush and is still stealthed.

If you have an oracles and no wards in the bush, you cannot see him, which is the case you're suggesting.

This case is that you have oracles and a green ward in the bush he's in. You can see him because the green ward extends your vision into the bush, and shaco is inside the oracle's radius. In the same way here, Heimer can see into the bush because his turret is there, and he's inside Eve's detection radius.

It's actually a bug now. If you have oracle's outside a bush and a ward inside the bush right next to you, your truesight is not supposed to work in the bush. Truesight is supposed to be seperate from vision but they either bugged it or changed it without putting it in patch notes.

Doesn't sound like one. If your sight range extends into brush and you have ways of detecting stealth within the same radius it should detect stealthed units.