“(1) First, establish what facts the taxpayer asserts give rise to a reasonable excuse (this may include the belief, acts or omissions of the taxpayer or any other person, the taxpayer's own experience or relevant attributes, the situation of the taxpayer at any relevant time and any other relevant external facts). (2) Second, decide which of those facts are proven. (3) Third, decide whether, viewed objectively, those proven facts do indeed amount to an objectively reasonable excuse for the default….In doing so, the Tribunal should take into account the experience and other relevant attributes of the taxpayer and the situation in which the taxpayer found himself at the relevant time or times. It might assist the Tribunal, in this context, to ask itself the question “was what the taxpayer did (or omitted to do or believed) objectively reasonable for this taxpayer in those circumstances?” (4) Fourth, having decided when any reasonable excuse ceased, decide whether the taxpayer remedied the failure without reasonable delay after that time (unless, exceptionally, the failure was remedied before the reasonable excuse ceased). In doing so, the FTT should again decide the matter objectively, but taking into account the experience and other relevant attributes of the taxpayer and the situation in which the taxpayer found himself at the relevant time or times.”