I disagree. Lack of supporting evidence in this case does amount to evidence against US since the burden of proof is on the claim that US is not only effective, but also worth the opportunity cost of not being able to use alternative, more active interventions during a treatment session due to the time wasted on US. What criteria would you accept as evidence against the effectiveness of US or any other treatment intervention? If an intervention can not be demonstrated scientifically to provide a significant benefit besides placebo (for how PTs typically utilize US), then what else would you need to see as evidence against it?