Looking at it realistically, this cop made terrible orders and handled the situation poorly. The consequence of the event is because of his poor judgment.
1. The cop should have asked if they had anything to drink, NOT if they were drunk. One drink is all it takes for your body to be affected by alcohol (reduced reaction time, impaired cognitive processing).
2. When asked if they could understand and obey his orders, they say yes even though they have both had drinks. People, when intoxicated, overestimate their abilities. That's why we have people who think they can drive under the influence. *cough* *cough*
2.5. Not necessarily the cops fault, more on the department, but cops should be trained to be able to identify if someone is inebriated.
3. The cop should have ordered them to simply lay down with their hands out in front. Then handcuff them one at a time, not have them do some stupid and unnecessary crawl.
Did Daniel fuck up by not telling the cops he had something to drink? Yes. But, because of the cops poor judgment, training, and orders, someone needlessly died.
EDIT: Let's not forget that on top of having drinks, Daniel was obviously scared shitless. Cops feel scared in these situations too, I think we can all agree on that. But cops are and MUST be held to a higher standard. They are trained to remain calm and think logically in all situations. If you are unable to do that when there is an intoxicated and scared man, you are in the wrong job and should be held accountable for the incident.