Yes it is, but Hustini is being Hustini. The problem with Llorente is that right now he isn't good enough to be in that position. It's ok if you have a Drogba in his prime or maybe Diego Costa, but Llorente isn't mobile enough or playing well enough to be effective at it.
It's obvious that he only stayed on because of a tactical decision, which was the right one for this game. In an open two-legged knock-out we have to see Morata in at least one of the games.
Yes Hustini is being Hustini.
Fact of the matter is, isolated or not, the guy couldn't even get into a position where one of his apparent strengths (heading) could be useful. He had plenty of service he was way outperformed by the defense marking him. If that makes him isolated, by the fact of being outplayed, then sure, he was isolated. We used to see a striker (Llorente) score using various parts of his body making him harder to mark. We can't even get ONE part of his body to work consistently, be it his right foot, head, etc. He flat out sucks right now and needs to get his act together because the "few" chances he seems to be getting don't even come close to looking like they will end up making the GK work.