I have been rescuing reptiles for quite sometime, longer than I've kept them as pets. Unfortunately, that's what a lot of people think. A Burmese gets 20' or more, people think zoos, collectors, etc. will take them. Sadly, this isn't the case. I've had five 16' plus Burmese pass through my house and most of them took over a year to re-home. Zoos don't need them, most collectors don't want them. Most of the people that inquire are just likely to end up causing themselves and/or the animals suffering.
I'm not saying that particular case couldn't have been handled differently. I'm saying, in most cases, it's very hard to find a "tame" 20' Burmese a decent home.
It's very sad that it has come down to these wonderful animals being euthanized. I won't argue on that point.