A spin chain extending from Alice to Bob with nearest neighbors interactions, initially in its ground state, is considered. Assuming that Bob measures the last spin of the chain, the energy of the spin chain has to increase, at least on average, due to the measurement disturbance. Presumably, the energy is provided by Bob's measurement apparatus. Assuming that, simultaneously to Bob's measurement, Alice measures the first spin, it is shown that either energy is not conserved, – implausible – or the projection postulate doesn't apply, and that there is signalling. An explicit measurement model shows that energy is conserved (as expected), but that the spin chain energy increase is not provided by the measurement apparatus(es), that the projection postulate is not always valid – illustrating the Wigner–Araki–Yanase (WAY) theorem – and that there is signalling, indeed. The signalling is due to the non-local interaction Hamiltonian. This raises the question of whether a suitable quantum-information-inspired model of such non-local Hamiltonians can be developed.