I found this problem in Windows 10 Edition on PC.

Problem :
Sprint is also available in the wrong methods. It can happen suddenly usual, and it makes the players put in unpredictable danger.

Details :
You can do the sprint in the following strange ways,

1) While standing, Hold W and tab A/S/D once less than 1 sec. Do not release W.
2) While walking forward, tab A/S/D twice. Do not release W.

These ways can usually occur while building, keep a distance during combat, walk on the pit. So it causes a brutal accident.

Thanks.

Test Environment :
Windows 10 Edition 0.14.1 with Keyboard