Interesting that they worded it that way, good to discuss that too. And that may be what they posted on a public website, but I wouldn't trust that the actual code doesn't mention operation.
From:
Chapter 8.60 UNMANNED AIRCRAFT SYSTEMS
(linked to from the city webpage, and it has a link at the bottom back).
8.60.030 Prohibition.
(a) Unless otherwise exempt under this chapter, drones or UASs are prohibited from being deployed, launched
or flown in any airspace within or over any sporting and/or large venue special event, including but not limited to over and within one-half mile of Levi’s® Stadium, over Santa Clara University sports facilities when they are in use, and over
public parks and public facilities during large venue special events.
So, you might be able to beg an officer to not ticket you as a misunderstanding, the officer could also just say, sorry, fight it in court. A lawyer could argue that the language is not legal because it says flying over, but then at the same time, to me that implies a violation if the PIC is actually on the park property. And a judge may decide to interpret the intent of the law instead of the actual language. Also, that lawyer may cost way more than the fine or permits. I don't think I would risk it myself. I'd rather find a private property location to do the same.
I also can't say 100% that this covers the correct Santa Clara (County vs City...). However, it should be considered, and if they say you can't launch or land, they probably mean operate as well (as the actual code/law implies).
At the same time, launching from the AMA field and the PIC remaining on the AMA side, and flying over the park to film friends, I don't see how they could even lawfully ticket you. I see no ambiguity in that. However it would prevent filming the pilot and depending on the situation, may not allow VLOS at low altitude. I would also consider it risky to be filming someone from in front or the side from much distance at all, like I would want more than 100' of distance (combined altitude and lateral) if I were more than 100' away. (side note, maybe use FPV with a VO under rec?)
You might get out of the fine on a technicality, or you might get a huge lawyer bill and still pay the fine.
So point is, just because a non-legal informational site probably written by lay-persons doesn't say operation, that doesn't mean the law doesn't say it. I believe (not a lawyer) that the prohibition of "Flown within any airspace within... a public park" pretty much sums it up.