You were absolutely right!
Previously I did tests at home, where I used MagSafe from my "home" computer - MacBook White. I didn't notice they are of different power! MacBook's White 13'' one - 60 W, MacBook's Pro 15''' one - 85 W. When doing new test with MagSafe taken out of my bag - 85 W one - MacBook Pro didn't hibernate after pulling the battery off.
Thanx a lot for hint ... I didn't notice the power difference - due to Apple's unificated design.