Sorry he's bein a prat!
As I have no arena of any sorts, I would force Bandit to just get on with things. I currently have fields that resemble lakes and/or giant mud puddles to ride in if I don't feel like chancing the road - I dream of sand.. and an indoor? Yes puhleeze!
Tell Puck to sort himself out, that Bandit has no choice but to get rained on so he should consider himself thankful :)
Stop for a minute, open your mind, learn. You may not agree with what I say, I may not agree with what you say but we will both learn something new.