Snakes including boa constrictors, do not produce slime trails when they move. But after regurgitating prey, there might be digestive fluid on the prey. Although swallowing a grown adult is unlikely. Large prey is swallowed but the animal is unable to move very far afterwards and may not need to eat again for another year.
No criminal activity can carry on under protection of diplomatic immunity. The suspect would either be declared persona non grata and be forced to leave the country, or the foreign government (not the family) would be asked to revoke it. Since immunity belongs to the government and not the individual, the father cannot invoke or revoke diplomatic immunity on the part of a family member.
At the end of episode the officer is cuffing Clavo Cruz, Gonzalo Menendez when the camera is in close range. The camera pans to the wide shot as General Antonio Cruz, Castulo Guerra, is leaving, and Clavo is standing with his hands to his sides. The officer is just standing behind him with bis hands to his sides as well.