As I remember it, they thought it was an AN-26 which is capable of FL250 or so but no higher.
Here’s the intercept transcript release by Ukraine: http://www.ibtimes.com/mh17-crash-full-transcript-alleged-phone-intercepts-between-russian-intelligence-1631992
Thing is, MH17 would have been a lot higher that an AN-26 is capable of, plus it had its blasted transponder on. There’s no excuse.
Drunk and Russian is no way to go through life, son.