This is not true. If the ACARS went through a normal log-off sequence then it was shut down deliberately. If it just stopped reporting then it could have been some other reason. As it has been said multiple times 'the ACARS was deliberately switched off' that implies that it went through a log-off sequence and tidy shut down, something it would NOT have done if the power to it was cut by the circuit breaker being tripped.
Can you share that tidy shutdown sequence from the ACARS protocol with us?