Gavin? The one commanding 82nd, who was behind the failure of Market-Garden?
Gavin and the 82nd were not responsible for the failure of Market Garen, the blame lies with Browning and Monty
Normally (at least here in Britain), the fight of the British 1st Airborne Division at Arnhem gets most of the coverage in accounts of Market-Garden, with very little space reserved for the fighting at Nijmegen. Interestingly, it was German veterans after the war who noted that it was the fighting at Nijmegen that decided the battle, and the fate of the British 1st Airborne.
The main factor is that 82nd Airborne did not make a major effort toward the poorly guarded Nijmegen Bridge right after the airdrop. In fact only two companies were dispatched toward the bridge late in the day and they were stalled by hastily deployed SS reinforcements. So while Gavin's overall record of generalship was good. During Market Garden that he erred on the side of force protection over mission accomplishment. A costly mistake given the nature of the operation the need secure the bridge ASAP.
Gavin wanted to secure his flanks before pushing into the city and did not expect significant German defences. This was a mistake. Consequently, the 82nd Airborne did not secure the Nijmegen Bridge until D+3, which doomed the British effort at Arnhem.
Of course British failure to exploit the American seizure of the Nijmegen Bridges on 20 September is often brought up as an excuse; (the Americans on the spot criticized the British armour units for failing to push on the 10 miles to Arnhem). But there were sound military reasons for not pushing on without infantry support, (if they had it probably would have yielded a column of burning Sherman hulks along the road to Arnhem). The failure exploiting fleeting opportunities - particularly ones that could decide battles - like Nijmegen was the responsibility of Gavin as he was the commander on the spot.