回想起来，他们似乎很可能疏忽了。用英语怎么说？

回想起来，他们似乎很可能疏忽了。

Retrospectively, it seems as if they probably were negligent.

retrospectively

adv. 回顾地；

例句
Method CT manifestations of 60 children with adenoid hypertrophy were retrospectively analyzed.
方法:回顾分析60例儿童腺样体肥大的CT表现.

it

pron. 它，他，正好是所需的，事实[情况]；n. <美俚>傻瓜，笨蛋，<俚>绝妙的人，理想的东西，登峰造极；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

seems

v. 好像，仿佛（ seem的第三人称单数 ）；

例句
Almost like an accident of nature, this family has produced more talent than seems possible.
就像是天缘巧合，这个家族不可思议地人才辈出。

as

adv. 同样地，一样地，例如；prep. 作为，以…的身份，如

例句
As far as I can recall, Patti was a Smith.
我记得帕蒂是姓史密斯的。

if

conj. 如果，倘若，即使，〈口〉是否，假设；n. 条件，设想；

例句
She was old enough to absent herself from the lunch table if she chose...
她长大了，可以自己做主不来吃午餐了。

they

pron. 他/她/它们，人们，大家，政府，当局，她们；

例句
The storms had abated by the time they rounded Cape Horn.
他们绕过合恩角时，暴风雨已经减弱。

probably

adv. 大概，或许，很可能，备不住；

例句
To stop the fighting there requires the threat and probably the actuality of military force...
要平息那里的战火就要威胁采用甚至真正动用军事力量。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

negligent

adj. 疏忽的，粗心大意的，不留心的，懒散；

例句
The jury determined that the airline was negligent in training and supervising the crew...
陪审团裁定航空公司在对全体机组人员的培训和管理问题上存在疏漏。