Double no show

At our recent competition there were multiple matches where both teams from an alliance didn’t show up. The manual states

Though the refs ruled it as with neither team showing up even if the alliance was there scored for the no show alliance they would get no strength points. I’m wondering was this the right call? Thanks in advance!

Yes, this was correct. In a match where both teams on an alliance were disqualified or noshows, the disqualified/no show alliance receives no WPs and no SPs. While their opponent alliance receives their own score as their SP for that match.