The presenter is a penetration tester from a security company. Pentesters have some pretty hairy skills and a lot of the video is pretty technicalbut there's some good demos that have Hollywood beat, in that they aren't fictional and don't involve screens, smoke or mirrors, or a lot of drama.
He says he reviewed only a few companies and doesn't claim what he found applies to every manufacturer but since they all probably use the same web browser, called "lightly", an open source BSD app lighttpd, it's quite probable they share essentially the same vulnerabilities. But what he does say about the systems he reviewed is very interesting.
A lot of his assessment was based on analyzing the upgrades, which saved the expense of buying the camera but gave the same information. One of the issues raised was changing the stored video, if this isn't adequately protected it isn't likely to have much value unless the court doesn't understand the issue.
Another one is if the system is facing the internet without any protection it's going to get scanned which raises the possibility it might provide an entry to the rest of the network. I've seen PC's with fresh OS installs get discovered and probed a lot sooner than I thought possible, no idea who it was, could have been a bot-net herder, or breeder. Probably how they were reproduced.
These are issues that might be worth considering, so far no has pointed any fingers at anyone over this but it's probably an issue that warrants more attention, and at least some caution. This stuff can sound scary, but that's not the point, it's better to have some awareness of the issue so as to protect oneself.