Have a think:
If you say "No, I won't do that." - the runway is blocked until a tug can remove the aircraft.
If you say "Yes, I'll have a go." - then you either taxi off successfully (hooray for everyone
) or the nose wheel steering proves not up to the challenge, in which case you apply the brake and the aircraft is slightly turned on the runway, but other than that situation one applies.
Unless you completely stuff up the point at which you give it away and apply the brakes (in the VERY unlikely event the nose wheel steering/differential braking isn't good enough) there is quite a bit to win and nothing to lose by taxiing off.