first off...
RIP Lv. 100 AIRMAN 3/21-3/21

so, here's how it happened:

1. played on windows phone
2. wanted to switch airman back to wily
3. buttons glitched and wrapped around.
4. when I clicked airman, there was no data
5. refreshed page to find airman didn't exist.
6. re-unlocked him
so, here is my suggestion (for now):
refrain from switching robots on primitive browsers in general.

Adrian Edit on 2019/01/31 - I believe this issue has been fixed or is otherwise not possible in today's build, but the thread is so old at this point it's hard to test. Please create a new thread if this issue pops up again, and apologies for the inconvenience.