Abdullah Ibn Khatal was a companion of Prophet Muhammad (p), sent out for a mission to collect alms (tax). A slave accompanied him. When they came to a place to rest, Abdullah told the slave to cook some food. Instead of the slave following orders, he was exhausted and ended up sleeping. When Abdullah woke up to see no food was prepared, he became vexed and attacked the slave and ended up killing him.
Abdullah was scared to go back to the Prophet (p) on what he had done because if he did so, he would have been killed for unlawfully taking a life. Hence, Ibn Khatal became a disbeliever and joined the enemies of the Prophet, the Quraish. So, when Prophet Muhammad (p) conquered Makkah, he was one of those whom the Prophet (p) had ordered be killed.
Scholar Maulana Wahiduddin Khan:
Abdullah ibn Khatal, who had previously accepted Islam been sent by the Prophet to collect alms tax. A slave and one of the Ansar went along with him. Coming to a halt in their journey, Abdullah ibn Khatal told the slave to prepare a chicken for a meal, but the slave went to sleep instead, and was unable to prepare the food in time.
Abdullah ibn Khatal became angry and killed the slave. Fearing that if he returned to Madinah, the Prophet would exact retribution for the slave’s death, he reneged and joined the infidels.
A poet, he used to recite verses abusing the Prophet. On the day Makkah was conquered, he wrapped himself up in the curtain of the Ka’bah. When the Prophet was told, he gave orders for Abdullah ibn Khatal to be killed in that very place. Abu Burzah and Sa’d ibn Harith executed him in between the Black Stone and the Place of Abraham. 
Mamar Ibn Rashid:
Ibn Khatal (Hilal ibn Abd Allah ibn Abd Manaf al-Adrami) (d. 8/830) One of the handful of persons whose death Muhammad ordered upon his conquest of Mecca. Ibn Khatal embraced Islam and undertook the Hijrah to Medina, after which the Prophet appointed him a collector of the alms-levy (al-sadaqah).
He apostatized after he killed a slave in fit of fury because the slave neglected to prepare his meal. He then fled to Mecca seeking refuge, fearing that Muhammad would execute him for his crime. 
Professor Taha Jabir Alalwani:
ABD’ALLAH IBN KHATAL
Ibn Ishaq states Abd Allah ibn Khatal was a man of the tribe of Banu Taym ibn Ghalib, and orders were given to kill him [on the day when Makkah was conquered]. A Muslim, he had been sent out by the Messenger of God as an alms collector, and one of the Supporters was sent out with him; he also had a Muslim servant with him.
They stopped somewhere to camp and Abd Allah ibn Khatal instructed the servant to slaughter a billy-goat and prepare him some food. He then went to sleep. When he awoke and the servant still hadn’t prepared anything for, he attacked him and killed him, then turned apostate and reverted to polytheism.’
This man, then, was guilty or murder as well, and his apostasy was an additional offense, He was a highway robber, a thief, and someone who had behaved in and untrustworthy manner with public funds, In addition, he went to war against the Messenger of God and incited others to fight against him.
Abd Allah ibn Khatal is mentioned by al-Baladhuri, whose account differs little from that of Ibn Ishaq. He states:
‘He embraced Islam and emigrated to Madinah, after which the Messenger of God sent him out as an alms collector. He sent with him a man from the tribe of Khuz’ah, whom he attacked and killed.’ The reason was that when Abd Allah ibn Khatal came one day and found that he [the man from khuza’ah] had not prepared any food for him, he flew into rage and beat him to death.
Then he said, Muhammad will kill me for this,’ so he apostatized and fled, taking the alms that were with him/ He betook himself to Makkah, saying to its people, ‘I have found no religion better than yours,’ Abd Allah ibn Khatal had two songstresses who used to satirize the Messenger of God in song.
And the polytheists would gather with him to listen to them and drink wine. On the day when Makkah was conquered, the Messenger of God said, ‘kill him even if he is clinging to the covering of the Ka’bah,’ and he was killed by Abu Barzazah al-Aslami… 
 Muhammad: A Prophet for All Humanity By Maulana Wahiduddin Khan, page 327 – 328
 The Expeditions: An Early Biography of Muhammad By Mamar Ibn Rashid, page 329 [Glossary]
 Apostasy in Islam: A Historical and Scriptural Analysis By Taha Jabir Alalwani, page 51 – 52