i can think of a few excuses and senility is one.
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regardless, if true,* this whole episode was a humiliation of muslims. in a fatwa mawlana amjad ali was asked whether the nikah conducted by a heretic (anti-madh'habite, ghayr muqallid) was valid. he replied that, if 'ijab-qabul' is conducted by even a kafir, the nikah would remain valid. and adds: 'however, one should not ask kafirs to do this because, this act indicates showing respect to kafirs and giving respect to kafirs is haram'.
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why should an elderly muslim, touted as a 'king' degrade himself in front of a pope? he should have told the pope : 'don't say three. there is only One.'
tawadu'u is in front of muslims, not in front of kafirs. one should be proud and wear their pride on their sleeve - this pride is not for one's own self. this is pride of islam.
ruHama'u baynahum - merciful to muslims; but ashidda'u `ala'l kuffar: harsh with kafirs. courtesy is something else. even if he met the pope, he could have just met him as it is not wrong to meet leaders of other religions. many ulama in the past have met with leaders of other religions - BUT without humiliating themselves and islam by extension.
this is why, the scrupulous amongst our ulama shunned company or visitation of kings and rulers.
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sayyiduna ghawth al-a'azam raDiyallahu 'anhu, had a way of meeting rulers. the visitor would arrive in the sitting room and when they were seated, sayyiduna ghaws e a'azam would enter the room obviating the need to stand up (which would be courtesy, but standing up is also a mark of respect) for rulers and kings.
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the kafir's prayer is nothing, but astray.
ulama warn against praying for kafirs - except the prayer of guidance. asking them to pray for us (particularly a religious head) is as if respecting their religion and borders on the kufr. (though we cannot claim this unless the man himself says whether his request was spontaneously due to habit; or whether he indeed thought that his prayer would benefit him)
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of the mountains:**
yusuf ibn asbaT says that he hear sufyan al-thawri say: 'by Allah! i swear by Him, and there is no god except Him: it has become permissible in our times to withdraw into seclusion (uzlah). [al-ghazali adds]: if it was permissible in those times, it has become mandatory in our times.
also attributed to sufyan is that he wrote to al-khawwaS [raHimahuma Allah]: verily, you are in those times, from which the companions of sayyiduna Muhammad sallAllahu alayhi wa sallam sought refuge of Allah and that they don't see such times [as we live in]. and they had knowledge that we don't; then how about us, who are lesser than them in knowledge, lesser in patience, wanting in aid [in religion], and [faced with the increase in] the murkiness of the dunya and the corruption of people living in it?
because sayyiduna umar ibn al-khattab radiyallahu anhu said: 'there is comfort and relief in seclusion, than in evil company'. and it is in this regard, the following lines have been said:
hādha’z zamānu’l ladhī kunnā nuĥādhiruhu
fī qawli kaábin wa fī qawli’bni masúūdī
dahrun bihi’l ĥaqqu mardūdun bi ajmaýihī
wa’ž žulmu wa’l baghyu fīhi ghayru mardūdi
in dāma hādha wa lam yaĥduth lahu ĥadathun
lam yubka maytun wa lam yufraĥ bi mawlūdi
this is an age, about which, we were warned against
in the sayings of kaab and ibn mas'ud
an age in which truth is totally rejected
and oppression, rebellion is not rejected
if this continues, and nothing happens to change the situation
there won't be sorrow for the departing dead; nor celebration for the newborn
laa Hawla wa laa quwwata illah billah. for abdu'l qadir: there is a difference between insulting RasulAllah sallAllahu alayhi wa sallam and committing harams. don't mix up the two.
*there seems little evidence to the contrary, but still strange things happen and one ought to be cautious. wa billahi't tawfiq.
** from minhaj al-abidin attributed to imam ghazali.