To reproduce:
1. Create new project
2. Create an empty game object, add Rect Transform component to it.
3. Paste number '9999999999999' to Rect Transform z rotation input field

Expected: number should be changed to previous value, warning message should be showed (number is too large)
Actual: z value is changed to -7.730941e+11 (as expected), but x and y values are changed to -180 and 180

Note: the same results are with all x,y and z axis

Reproduced on: 5.4.5p2, 5.5.3p3, 5.6.0p3, 2017.1.0b4
Not reproducible 5.3.7p4