This is simply untrue, and I believe I've corrected it elsewhere. Please stop repeating it.
If you have more information, I am interested in that.
The reasoning is simple: In order to break ECC, you would have to perform the "discrete logarithm"
in both cases, both for ECIES and ECDSA.
Use of ECIES also use conventional encryption such as AES which should also be cryptographically strong.
But the assumption is that the conventional crypto is sufficiently strong.