Actually, in the OP's link (the news story), at the 17 second point, it shows the sheriff saying that he asked him to get back, with Jackson responding "no you didn't", then launching into a swear word filled tirade. That was from the bodycam footage and the sheriff told Jackson that he had already asked him to get back.
At around the 27 second point in the OP's link, the news anchor even states as part of the report that Jackson had been asked repeatedly by not only the officers, but bystanders as well to move out of the way so that the EMTs could do their job.
Watch the link. Jackson was acting like a total ass, and doing his best "I know people" (he threatened to call the governor) and "don't you know who I am" routine.