What CW actually said on his phone call to the school (discovery page 663), slightly snipped by me:
On 08/15/18 I, Colorado Bureau of Investigation (CBI) Agent MATTHEW SAILOR, responded to Primrose School of Erie at Vista Ridge located at 2998 Ridge View Drive in Erie, Colorado to conduct follow up. Primrose is the school of BELLA WATTS and CELESTE WATTS, who did not show up for the first day of school on 08/13/18. It was reported that their father, CHRIS WATTS, called the school to advise they would not be attending.
Upon arrival at approximately 1220 hours, I met with the owner, CHRIS LANG, and spoke with him in his office. LANG said that both BELLA and CELESTE had attended the school last year, and that their mother, SHANANN WATTS, had pulled them out for the summer because she was taking them to North Carolina for an extended trip. LANG said that both girls were scheduled to start at the school again when the new year started on 08/13/18. LANG said that between 0800 hours and 0815 hours SHANNON MEYER received a phone call from the girls’ father, CHRIS WATTS, stating they would not be attending the school. LANG said that CHRIS then asked MEYER if the girls were at the school. LANG said that MEYER was “freaked out” by the phone call and later reported it to police.
[...]
I then spoke with MEYER by phone (speakerphone in the office). MEYER said that CHRIS called at about 0815 hours on 08/13/18, and said that after he introduced himself she told him that they were expecting to see the girls starting at the school and he replied that he was calling to let them know that the girls weren’t going to start. He said he wasn’t really sure what was going on yet, but that they were going to be moving and putting the house up for sale, and they were not sure if they were going to stay in this area. MEYER responded with, “That’s pretty crazy.” MEYER said that CHRIS then asked, “The girls aren’t there, are they?” MEYER said she told CHRIS no, she hadn’t seen them, but to let her check and see if they were clocked in, and they were not clocked in. CHRIS said ok, and to put them down as not coming in, and MEYER asked if he wanted to be placed on a waiting list in case something changes. CHRIS replied that they might as well,but they weren’t sure what was going on. MEYER told him to keep them updated, and that the teachers would be sad to not see the girls today. CHRIS thanked her and then hung up.