Not at the time. Sometimes they don't find out until AFTER they investigate.
They investigated the call on the first warrant and did not remove any children then. They got they second warrant on the evidence of child abuse they observed when investigating the first warrant, spent several hours interviewing people there. They got the runaround and lied to so they finally decided to remove the kids until they straightened things out.
The cultists are the ones who did the lying. If they didn't like the outcome, they shouldn't have lied and played the CPS and LE for the fools. It backfired on them and they turned out to be the fools.
Typical cult apologist attitude, nothing the government is doing is good enough in this case. The government shouldn't have done anything without investigating thoroughly and gathering evidence beforehand, and now when they are gathering evidence they're accused of going on fishing expeditions.
They knew before the raid that Barlowe hadn't been in Texas for 20 years. (they have dropped his warrant).