Are there two rules in Hastings-Bass?

Three questions arise:
(a) Is it necessary to show that the
trustees would have acted
differently if properly directed:
In re Hastings-Bass deceased
[1975] Ch 25 (CA) Mettoy
Pension Trustees v Evans [1990]
1 WLR 1587? Or is it enough
that they might have done:
see Kerr v British Leyland
(Staff) Trustees [2001] WTLR
1071 (CA)?
(b) Is the effect of applying the
rule that the act of the trustees
is void : In re Abrahams' Will
Trusts [1969] 1 Ch 483? Or is it
voidable: Abacus Trust Company
(Isle of Man) v Barr, [2003] 5
ITELR 602?
(c) Is it necessary to show that
the trustees are at fault:
Abacus v Barr?

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