You could have mis-shifted. The BMW transmission mounts for E36 are notoriuously soft and under a heavy load, the transmission will torque, but the gear shift notches will not. So, when you upshift, you can moneyshift and blow some stuff up even though you put it in the correct gear notch. Not by any fault of yours, you can shift it into the correct gear, but the transmission is torqueing so it dosn't quite match up anymore.
Invest in some aftermarket urathane transmission mounts if it's mis-shifting and the clutch wasn't slipping.