Slot machines are on someone else's premises and (disclaimer: I've never been to a casino myself) are most likely under surveillance, so they'll probably void your winnings and ban you if you start doing something sketchy.
Devices that implement any restrictions against the end user like DRM or MDM, on the other hand, are in possession of the said user. I heard a saying that getting root privileges on a device you physically possess is only a matter of time and effort.
In other words, you can totally take your phone apart as much as your tools and skills allow, but you'll get arrested if you try taking a slot machine apart.