He did not believe his household seriously tainted with heresy.

He knew that certain of them who had been with him in London had imbibed the teaching of Dean Colet and his pupils, and he did not know, any more than the dean himself, that the Lollards secretly encouraged each other to go and hear a man who spoke so much of the truth they themselves held.
The line where orthodoxy ends and heresy begins has been at all times hard to define, and perhaps the upholders of the "Church" knew as little as anybody how hard this definition was becoming.
Several persons had stood forth (invited by the prior to do so) and confessed to dangerous sentiments which they now saw to be utterly wrong, and vowed to abjure forever; or had accused other persons of words which required explanation, or of deeds which suggested a leaning towards secret meetings where heresy might be discussed.
But the day's proceedings seemed drawing to a close, and nothing of any great peril to the Lord of Chad had occurred, when just at the close of the afternoon Brother Fabian suddenly came forward and whispered a few words in the prior's ear; and he, after a moment of apparent hesitation, spoke aloud.
"It is with great grief that I learn that one of our own brethren has been heard to utter words which sound strangely like those of heresy; but since it is our bounden duty that strict justice be done to all, whether high or low, rich or poor, nay, whether it be our own son or brother, I here call upon Brother Emmanuel to stand forth publicly, as others have done, and answer the charge brought against him." The prior looked round as he spoke these words in a loud voice; but there was no movement either in the crowd or amongst the cowled monks, and he spoke the name again without eliciting any response.
The Lord of Mortimer leaned forward and spoke to his neighbour.
"Methinks this brother was a member of your household, Sir Oliver," he said, with a gleam of malice in his eye.

"Surely you received a mandate bidding you come with all your household.

Where is this preceptor of your sons ?" "His duties ceased last night," replied Sir Oliver calmly, in a tone loud enough to reach the prior's ears.

"He had command to return today to the priory, and last evening he said farewell to me and mine.