The holy Quran answers your question itself:
By having accepted the first verse(8:16) and the fact that:
1) Whoever turns his back to the disbelievers and escapes from them in a war, will go to the hell.
Lets have a look at the second verse(9:25) and its following two verses(9:26 and 9:27)
لَقَدْ نَصَرَكُمُ اللَّـهُ فِي مَوَاطِنَ كَثِيرَةٍ ۙ وَيَوْمَ حُنَيْنٍ ۙ إِذْ أَعْجَبَتْكُمْ كَثْرَتُكُمْ فَلَمْ تُغْنِ عَنكُمْ شَيْئًا وَضَاقَتْ عَلَيْكُمُ الْأَرْضُ بِمَا رَحُبَتْ ثُمَّ وَلَّيْتُم مُّدْبِرِينَ
Allah has already given you victory in many regions and [even] on the day of Hunayn, when your great number pleased you, but it did not avail you at all, and the earth was confining for you with its vastness; then you turned back, fleeing. [9:25]
ثُمَّ أَنزَلَ اللَّـهُ سَكِينَتَهُ عَلَىٰ رَسُولِهِ وَعَلَى الْمُؤْمِنِينَ وَأَنزَلَ جُنُودًا لَّمْ تَرَوْهَا وَعَذَّبَ الَّذِينَ كَفَرُوا ۚ وَذَٰلِكَ جَزَاءُ الْكَافِرِينَ
Then Allah sent down His tranquillity upon His Messenger and upon the believers and sent down soldiers angels whom you did not see and punished those who disbelieved. And that is the recompense of the disbelievers. [9:26]
ثُمَّ يَتُوبُ اللَّـهُ مِن بَعْدِ ذَٰلِكَ عَلَىٰ مَن يَشَاءُ ۗ وَاللَّـهُ غَفُورٌ رَّحِيمٌ
Then Allah will accept repentance after that for whom He wills; and Allah is Forgiving and Merciful. [9:27]
2) And we believe that whoever Allah accepts repentance from him won't go to the hell (at least for that sin).
So according to the verse 9:27 we should change our first hypothesis to the following one:
(1) + (2) = Whoever turns his back to the disbelievers and escapes from them in a war, will go to the hell, except those ones Allah has accepted their repentance.
Is there any conflict yet in our holy Quran?