So, I keep getting that I'm constructing a negatively oriented tetrahedron but I get it sporadically so I'm not sure. Here's the github link : https://github.com/LeonineKing1199/HardWayHome
And unfortunately my code does use the library Eigen so if you wanna run it, it needs it.
But the thing about the error is, my walk function only collects tetrahedra in which the point I'm trying to insert is above all 4 faces so it's perfectly contained.
I don't know if that was enough explanation but valgrind seems to fix my error and I only get random crashes. It's not like I'm reading/writing wrong but rather, I'm getting odd negative fractures.