If a person dies in the bathroom, is that indicative of a bad end?

In such cases, if a person dies
in such circumstances, it has nothing to do with being praiseworthy or
blameworthy in and of itself, and there is no Islamic ruling connected to
that. Islamic rulings only have to do with the deeds of those who are
accountable. If a person dies in a particular place, or at a particular
time, or in a particular posture, that is not part of his deeds and it is
not within his control, so there is no ruling that is connected to it. 

With regard to the death of one
who is fasting, this is the matter concerning which there are reports which
point to its virtue, not because death in this situation was within his
control, but because he died whilst doing a righteous deed and his life
ended with that. It is the righteous deed that is within his control and is
connected to the ruling of Allah. If a person dies doing such a deed, that
is a blessing granted by Allah, may He be exalted, to His slave, and it is
encouraged to constantly do such deeds, in the hope that one might die doing
such a thing. 

It was narrated that Hudhayfah
(may Allah be pleased with him) said: The Prophet (blessings and peace of
Allah be upon him) said: “Whoever fasts one day, seeking the Countenance of
Allah, and his life ends with that, will enter Paradise.”

Narrated by Ahmad (no. 22235).
Shaykh al-Arna’oot said: It is saheeh because of corroborating evidence. 

It was also narrated by al-Bazzaar
in his Musnad (1/436) as follows: “If a person’s life ends with a day
of fasting, he will enter Paradise.” Classed as saheeh by Shaykh al-Albaani. 

Al-Mannaawi (may Allah have
mercy on him) said: The words “If a person’s life ends with a day of
fasting” mean: if a person’s life concludes with a day of fasting, in the
sense that he dies when he is fasting or after breaking his fast. 

The words “will enter Paradise”
mean: with those who enter it first, or without prior punishment.

End quote from Fayd al-Qadeer
Sharh al-Jaami‘ as-Sagheer (6/160) 

Muslim narrated in his Saheeh
(5126) that Jaabir said: I heard the Messenger of Allah (blessings and peace
of Allah be upon him) say: “Each person will be resurrected in the condition
in which he died.” 

Ibn al-Jawzi (may Allah have
mercy on him) said: If a person dies in a particular condition, then his
life ends with that, and in that condition he will be resurrected.

End quote from Kashf al-Mushkil
min Hadeeth as-Saheehayn (1/751) 

And Allah knows best.