This is fairly common from time to time. Honestly there are times when people bet 0.10 BTC all day long and got like 50-100 BTC in losses and don't seem to mind it. Sure its alot of money but most likely this was some early adopter who might of mined BTC with their CPU back in 2009.
Remember a few days back when that dormant 50 BTC transaction took place? That guy signed about 150 other addresses he owned with 50BTC so >$50,000,000 or so. Probably could have more funds in other accounts.
Hence for someone with $50,000,000 of net worth, gambling away $50K is nothing. Its no different from a small gambler to gamble $200 and either win $200 or lose $200.
It is still a lot of money, even if you are a rich person that owns that much money. Just because you can afford it doesn't suddenly make it cheap. If Jeff Bezos plays with 0.1 bitcoin per bet and loses 100k at the end, that is still a lot of money. The exact reason is, gambling is more like fun thing, if you are super rich and don't mind losing 50k or 100k, that means you are not doing it for the money, but you are doing it for fun.
Especially when you are super rich your life becomes very stressful since how you made that money also causes you stress. So, having a relax time gambling looks like the main reason for them. However for 100k, you could have so much more fun somewhere else, it all depends on what you like to do but 100k opens a lot of doors and honestly I would rather do something else to relax and have fun instead of gambling for that much money. Personal differences of course, that is just me.
So, answer lies in your post. A lot is a little bit complex definition. If you have 100$, then 10$ may be a lot for you (10% of total budget) but if you have 100 000, then 10$ may be nothing for you (0.01% of your budget).
Another important factor there is how you have earned money. When money suddenly comes out of thin air (lottery wins, thousands of bitcoins mined in past and etc), then it's much easier to spend like nothing. That's why some people easily lose tens of bitcoins and even more easily.
Also if you are super-rich, you can even buy casino too and gamble with your money the way you wish + get them back
jamyrOnce I had the same question about live statistics of wagering contest too and despite the fact that support was a little bit confused (maybe he/she was new), they didn't forget my question and the next day I got a detailed answer on everything.
rammy2k2Bitsler rocks as usual.