Issue still reproducible in 15w34d.
Added 1.8.7 F5 screenshot and inventory screenshot.
Still in 1.8.7.
confirmed 14w31a
It also seems to happen with any value where 90 is, essentially:
tp @p ~ ~ ~ ~ ~number
and the view will rotate while the chat is open.
Nope, looks like it's been resolved - can anyone close this issue?