He's shocked when he finds what's on the bottom.
Possible solution

Kevin's colleague gave the report of the vet to the rest after the call. The snake could be pregnant and is close to laying her eggs at the center of the pit. The vet wanted to be sure, so they asked to find the exact location of the bulge. To do this they needed to get the snake on the ground. Kevin's co-workers were not all willing to do it.